1 /*
   2  * Copyright (c) 1997, 2026, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "asm/macroAssembler.hpp"
  26 #include "asm/macroAssembler.inline.hpp"
  27 #include "ci/ciReplay.hpp"
  28 #include "classfile/javaClasses.hpp"
  29 #include "code/aotCodeCache.hpp"
  30 #include "code/exceptionHandlerTable.hpp"
  31 #include "code/nmethod.hpp"
  32 #include "compiler/compilationFailureInfo.hpp"
  33 #include "compiler/compilationMemoryStatistic.hpp"
  34 #include "compiler/compileBroker.hpp"
  35 #include "compiler/compileLog.hpp"
  36 #include "compiler/compiler_globals.hpp"
  37 #include "compiler/compilerDefinitions.hpp"
  38 #include "compiler/compilerOracle.hpp"
  39 #include "compiler/disassembler.hpp"
  40 #include "compiler/oopMap.hpp"
  41 #include "gc/shared/barrierSet.hpp"
  42 #include "gc/shared/c2/barrierSetC2.hpp"
  43 #include "jfr/jfrEvents.hpp"
  44 #include "jvm_io.h"
  45 #include "memory/allocation.hpp"
  46 #include "memory/arena.hpp"
  47 #include "memory/resourceArea.hpp"
  48 #include "opto/addnode.hpp"
  49 #include "opto/block.hpp"
  50 #include "opto/c2compiler.hpp"
  51 #include "opto/callGenerator.hpp"
  52 #include "opto/callnode.hpp"
  53 #include "opto/castnode.hpp"
  54 #include "opto/cfgnode.hpp"
  55 #include "opto/chaitin.hpp"
  56 #include "opto/compile.hpp"
  57 #include "opto/connode.hpp"
  58 #include "opto/convertnode.hpp"
  59 #include "opto/divnode.hpp"
  60 #include "opto/escape.hpp"
  61 #include "opto/idealGraphPrinter.hpp"
  62 #include "opto/locknode.hpp"
  63 #include "opto/loopnode.hpp"
  64 #include "opto/machnode.hpp"
  65 #include "opto/macro.hpp"
  66 #include "opto/matcher.hpp"
  67 #include "opto/mathexactnode.hpp"
  68 #include "opto/memnode.hpp"
  69 #include "opto/mulnode.hpp"
  70 #include "opto/narrowptrnode.hpp"
  71 #include "opto/node.hpp"
  72 #include "opto/opaquenode.hpp"
  73 #include "opto/opcodes.hpp"
  74 #include "opto/output.hpp"
  75 #include "opto/parse.hpp"
  76 #include "opto/phaseX.hpp"
  77 #include "opto/reachability.hpp"
  78 #include "opto/rootnode.hpp"
  79 #include "opto/runtime.hpp"
  80 #include "opto/stringopts.hpp"
  81 #include "opto/type.hpp"
  82 #include "opto/vector.hpp"
  83 #include "opto/vectornode.hpp"
  84 #include "runtime/globals_extension.hpp"
  85 #include "runtime/sharedRuntime.hpp"
  86 #include "runtime/signature.hpp"
  87 #include "runtime/stubRoutines.hpp"
  88 #include "runtime/timer.hpp"
  89 #include "utilities/align.hpp"
  90 #include "utilities/copy.hpp"
  91 #include "utilities/hashTable.hpp"
  92 #include "utilities/macros.hpp"
  93 
  94 // -------------------- Compile::mach_constant_base_node -----------------------
  95 // Constant table base node singleton.
  96 MachConstantBaseNode* Compile::mach_constant_base_node() {
  97   if (_mach_constant_base_node == nullptr) {
  98     _mach_constant_base_node = new MachConstantBaseNode();
  99     _mach_constant_base_node->add_req(C->root());
 100   }
 101   return _mach_constant_base_node;
 102 }
 103 
 104 
 105 /// Support for intrinsics.
 106 
 107 // Return the index at which m must be inserted (or already exists).
 108 // The sort order is by the address of the ciMethod, with is_virtual as minor key.
 109 class IntrinsicDescPair {
 110  private:
 111   ciMethod* _m;
 112   bool _is_virtual;
 113  public:
 114   IntrinsicDescPair(ciMethod* m, bool is_virtual) : _m(m), _is_virtual(is_virtual) {}
 115   static int compare(IntrinsicDescPair* const& key, CallGenerator* const& elt) {
 116     ciMethod* m= elt->method();
 117     ciMethod* key_m = key->_m;
 118     if (key_m < m)      return -1;
 119     else if (key_m > m) return 1;
 120     else {
 121       bool is_virtual = elt->is_virtual();
 122       bool key_virtual = key->_is_virtual;
 123       if (key_virtual < is_virtual)      return -1;
 124       else if (key_virtual > is_virtual) return 1;
 125       else                               return 0;
 126     }
 127   }
 128 };
 129 int Compile::intrinsic_insertion_index(ciMethod* m, bool is_virtual, bool& found) {
 130 #ifdef ASSERT
 131   for (int i = 1; i < _intrinsics.length(); i++) {
 132     CallGenerator* cg1 = _intrinsics.at(i-1);
 133     CallGenerator* cg2 = _intrinsics.at(i);
 134     assert(cg1->method() != cg2->method()
 135            ? cg1->method()     < cg2->method()
 136            : cg1->is_virtual() < cg2->is_virtual(),
 137            "compiler intrinsics list must stay sorted");
 138   }
 139 #endif
 140   IntrinsicDescPair pair(m, is_virtual);
 141   return _intrinsics.find_sorted<IntrinsicDescPair*, IntrinsicDescPair::compare>(&pair, found);
 142 }
 143 
 144 void Compile::register_intrinsic(CallGenerator* cg) {
 145   bool found = false;
 146   int index = intrinsic_insertion_index(cg->method(), cg->is_virtual(), found);
 147   assert(!found, "registering twice");
 148   _intrinsics.insert_before(index, cg);
 149   assert(find_intrinsic(cg->method(), cg->is_virtual()) == cg, "registration worked");
 150 }
 151 
 152 CallGenerator* Compile::find_intrinsic(ciMethod* m, bool is_virtual) {
 153   assert(m->is_loaded(), "don't try this on unloaded methods");
 154   if (_intrinsics.length() > 0) {
 155     bool found = false;
 156     int index = intrinsic_insertion_index(m, is_virtual, found);
 157      if (found) {
 158       return _intrinsics.at(index);
 159     }
 160   }
 161   // Lazily create intrinsics for intrinsic IDs well-known in the runtime.
 162   if (m->intrinsic_id() != vmIntrinsics::_none &&
 163       m->intrinsic_id() <= vmIntrinsics::LAST_COMPILER_INLINE) {
 164     CallGenerator* cg = make_vm_intrinsic(m, is_virtual);
 165     if (cg != nullptr) {
 166       // Save it for next time:
 167       register_intrinsic(cg);
 168       return cg;
 169     } else {
 170       gather_intrinsic_statistics(m->intrinsic_id(), is_virtual, _intrinsic_disabled);
 171     }
 172   }
 173   return nullptr;
 174 }
 175 
 176 // Compile::make_vm_intrinsic is defined in library_call.cpp.
 177 
 178 #ifndef PRODUCT
 179 // statistics gathering...
 180 
 181 juint  Compile::_intrinsic_hist_count[vmIntrinsics::number_of_intrinsics()] = {0};
 182 jubyte Compile::_intrinsic_hist_flags[vmIntrinsics::number_of_intrinsics()] = {0};
 183 
 184 inline int as_int(vmIntrinsics::ID id) {
 185   return vmIntrinsics::as_int(id);
 186 }
 187 
 188 bool Compile::gather_intrinsic_statistics(vmIntrinsics::ID id, bool is_virtual, int flags) {
 189   assert(id > vmIntrinsics::_none && id < vmIntrinsics::ID_LIMIT, "oob");
 190   int oflags = _intrinsic_hist_flags[as_int(id)];
 191   assert(flags != 0, "what happened?");
 192   if (is_virtual) {
 193     flags |= _intrinsic_virtual;
 194   }
 195   bool changed = (flags != oflags);
 196   if ((flags & _intrinsic_worked) != 0) {
 197     juint count = (_intrinsic_hist_count[as_int(id)] += 1);
 198     if (count == 1) {
 199       changed = true;           // first time
 200     }
 201     // increment the overall count also:
 202     _intrinsic_hist_count[as_int(vmIntrinsics::_none)] += 1;
 203   }
 204   if (changed) {
 205     if (((oflags ^ flags) & _intrinsic_virtual) != 0) {
 206       // Something changed about the intrinsic's virtuality.
 207       if ((flags & _intrinsic_virtual) != 0) {
 208         // This is the first use of this intrinsic as a virtual call.
 209         if (oflags != 0) {
 210           // We already saw it as a non-virtual, so note both cases.
 211           flags |= _intrinsic_both;
 212         }
 213       } else if ((oflags & _intrinsic_both) == 0) {
 214         // This is the first use of this intrinsic as a non-virtual
 215         flags |= _intrinsic_both;
 216       }
 217     }
 218     _intrinsic_hist_flags[as_int(id)] = (jubyte) (oflags | flags);
 219   }
 220   // update the overall flags also:
 221   _intrinsic_hist_flags[as_int(vmIntrinsics::_none)] |= (jubyte) flags;
 222   return changed;
 223 }
 224 
 225 static char* format_flags(int flags, char* buf) {
 226   buf[0] = 0;
 227   if ((flags & Compile::_intrinsic_worked) != 0)    strcat(buf, ",worked");
 228   if ((flags & Compile::_intrinsic_failed) != 0)    strcat(buf, ",failed");
 229   if ((flags & Compile::_intrinsic_disabled) != 0)  strcat(buf, ",disabled");
 230   if ((flags & Compile::_intrinsic_virtual) != 0)   strcat(buf, ",virtual");
 231   if ((flags & Compile::_intrinsic_both) != 0)      strcat(buf, ",nonvirtual");
 232   if (buf[0] == 0)  strcat(buf, ",");
 233   assert(buf[0] == ',', "must be");
 234   return &buf[1];
 235 }
 236 
 237 void Compile::print_intrinsic_statistics() {
 238   char flagsbuf[100];
 239   ttyLocker ttyl;
 240   if (xtty != nullptr)  xtty->head("statistics type='intrinsic'");
 241   tty->print_cr("Compiler intrinsic usage:");
 242   juint total = _intrinsic_hist_count[as_int(vmIntrinsics::_none)];
 243   if (total == 0)  total = 1;  // avoid div0 in case of no successes
 244   #define PRINT_STAT_LINE(name, c, f) \
 245     tty->print_cr("  %4d (%4.1f%%) %s (%s)", (int)(c), ((c) * 100.0) / total, name, f);
 246   for (auto id : EnumRange<vmIntrinsicID>{}) {
 247     int   flags = _intrinsic_hist_flags[as_int(id)];
 248     juint count = _intrinsic_hist_count[as_int(id)];
 249     if ((flags | count) != 0) {
 250       PRINT_STAT_LINE(vmIntrinsics::name_at(id), count, format_flags(flags, flagsbuf));
 251     }
 252   }
 253   PRINT_STAT_LINE("total", total, format_flags(_intrinsic_hist_flags[as_int(vmIntrinsics::_none)], flagsbuf));
 254   if (xtty != nullptr)  xtty->tail("statistics");
 255 }
 256 
 257 void Compile::print_statistics() {
 258   { ttyLocker ttyl;
 259     if (xtty != nullptr)  xtty->head("statistics type='opto'");
 260     Parse::print_statistics();
 261     PhaseStringOpts::print_statistics();
 262     PhaseCCP::print_statistics();
 263     PhaseRegAlloc::print_statistics();
 264     PhaseOutput::print_statistics();
 265     PhasePeephole::print_statistics();
 266     PhaseIdealLoop::print_statistics();
 267     ConnectionGraph::print_statistics();
 268     PhaseMacroExpand::print_statistics();
 269     if (xtty != nullptr)  xtty->tail("statistics");
 270   }
 271   if (_intrinsic_hist_flags[as_int(vmIntrinsics::_none)] != 0) {
 272     // put this under its own <statistics> element.
 273     print_intrinsic_statistics();
 274   }
 275 }
 276 #endif //PRODUCT
 277 
 278 void Compile::gvn_replace_by(Node* n, Node* nn) {
 279   for (DUIterator_Last imin, i = n->last_outs(imin); i >= imin; ) {
 280     Node* use = n->last_out(i);
 281     bool is_in_table = initial_gvn()->hash_delete(use);
 282     uint uses_found = 0;
 283     for (uint j = 0; j < use->len(); j++) {
 284       if (use->in(j) == n) {
 285         if (j < use->req())
 286           use->set_req(j, nn);
 287         else
 288           use->set_prec(j, nn);
 289         uses_found++;
 290       }
 291     }
 292     if (is_in_table) {
 293       // reinsert into table
 294       initial_gvn()->hash_find_insert(use);
 295     }
 296     record_for_igvn(use);
 297     PhaseIterGVN::add_users_of_use_to_worklist(nn, use, *_igvn_worklist);
 298     i -= uses_found;    // we deleted 1 or more copies of this edge
 299   }
 300 }
 301 
 302 
 303 // Identify all nodes that are reachable from below, useful.
 304 // Use breadth-first pass that records state in a Unique_Node_List,
 305 // recursive traversal is slower.
 306 void Compile::identify_useful_nodes(Unique_Node_List &useful) {
 307   int estimated_worklist_size = live_nodes();
 308   useful.map( estimated_worklist_size, nullptr );  // preallocate space
 309 
 310   // Initialize worklist
 311   if (root() != nullptr)  { useful.push(root()); }
 312   // If 'top' is cached, declare it useful to preserve cached node
 313   if (cached_top_node())  { useful.push(cached_top_node()); }
 314 
 315   // Push all useful nodes onto the list, breadthfirst
 316   for( uint next = 0; next < useful.size(); ++next ) {
 317     assert( next < unique(), "Unique useful nodes < total nodes");
 318     Node *n  = useful.at(next);
 319     uint max = n->len();
 320     for( uint i = 0; i < max; ++i ) {
 321       Node *m = n->in(i);
 322       if (not_a_node(m))  continue;
 323       useful.push(m);
 324     }
 325   }
 326 }
 327 
 328 // Update dead_node_list with any missing dead nodes using useful
 329 // list. Consider all non-useful nodes to be useless i.e., dead nodes.
 330 void Compile::update_dead_node_list(Unique_Node_List &useful) {
 331   uint max_idx = unique();
 332   VectorSet& useful_node_set = useful.member_set();
 333 
 334   for (uint node_idx = 0; node_idx < max_idx; node_idx++) {
 335     // If node with index node_idx is not in useful set,
 336     // mark it as dead in dead node list.
 337     if (!useful_node_set.test(node_idx)) {
 338       record_dead_node(node_idx);
 339     }
 340   }
 341 }
 342 
 343 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Unique_Node_List &useful) {
 344   int shift = 0;
 345   for (int i = 0; i < inlines->length(); i++) {
 346     CallGenerator* cg = inlines->at(i);
 347     if (useful.member(cg->call_node())) {
 348       if (shift > 0) {
 349         inlines->at_put(i - shift, cg);
 350       }
 351     } else {
 352       shift++; // skip over the dead element
 353     }
 354   }
 355   if (shift > 0) {
 356     inlines->trunc_to(inlines->length() - shift); // remove last elements from compacted array
 357   }
 358 }
 359 
 360 void Compile::remove_useless_late_inlines(GrowableArray<CallGenerator*>* inlines, Node* dead) {
 361   assert(dead != nullptr && dead->is_Call(), "sanity");
 362   int found = 0;
 363   for (int i = 0; i < inlines->length(); i++) {
 364     if (inlines->at(i)->call_node() == dead) {
 365       inlines->remove_at(i);
 366       found++;
 367       NOT_DEBUG( break; ) // elements are unique, so exit early
 368     }
 369   }
 370   assert(found <= 1, "not unique");
 371 }
 372 
 373 template<typename N, ENABLE_IF_SDEFN(std::is_base_of<Node, N>::value)>
 374 void Compile::remove_useless_nodes(GrowableArray<N*>& node_list, Unique_Node_List& useful) {
 375   for (int i = node_list.length() - 1; i >= 0; i--) {
 376     N* node = node_list.at(i);
 377     if (!useful.member(node)) {
 378       node_list.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
 379     }
 380   }
 381 }
 382 
 383 void Compile::remove_useless_node(Node* dead) {
 384   remove_modified_node(dead);
 385 
 386   // Constant node that has no out-edges and has only one in-edge from
 387   // root is usually dead. However, sometimes reshaping walk makes
 388   // it reachable by adding use edges. So, we will NOT count Con nodes
 389   // as dead to be conservative about the dead node count at any
 390   // given time.
 391   if (!dead->is_Con()) {
 392     record_dead_node(dead->_idx);
 393   }
 394   if (dead->is_macro()) {
 395     remove_macro_node(dead);
 396   }
 397   if (dead->is_expensive()) {
 398     remove_expensive_node(dead);
 399   }
 400   if (dead->is_ReachabilityFence()) {
 401     remove_reachability_fence(dead->as_ReachabilityFence());
 402   }
 403   if (dead->is_OpaqueTemplateAssertionPredicate()) {
 404     remove_template_assertion_predicate_opaque(dead->as_OpaqueTemplateAssertionPredicate());
 405   }
 406   if (dead->is_ParsePredicate()) {
 407     remove_parse_predicate(dead->as_ParsePredicate());
 408   }
 409   if (dead->for_post_loop_opts_igvn()) {
 410     remove_from_post_loop_opts_igvn(dead);
 411   }
 412   if (dead->for_merge_stores_igvn()) {
 413     remove_from_merge_stores_igvn(dead);
 414   }
 415   if (dead->is_Call()) {
 416     remove_useless_late_inlines(                &_late_inlines, dead);
 417     remove_useless_late_inlines(         &_string_late_inlines, dead);
 418     remove_useless_late_inlines(         &_boxing_late_inlines, dead);
 419     remove_useless_late_inlines(&_vector_reboxing_late_inlines, dead);
 420 
 421     if (dead->is_CallStaticJava()) {
 422       remove_unstable_if_trap(dead->as_CallStaticJava(), false);
 423     }
 424   }
 425   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 426   bs->unregister_potential_barrier_node(dead);
 427 }
 428 
 429 // Disconnect all useless nodes by disconnecting those at the boundary.
 430 void Compile::disconnect_useless_nodes(Unique_Node_List& useful, Unique_Node_List& worklist, const Unique_Node_List* root_and_safepoints) {
 431   uint next = 0;
 432   while (next < useful.size()) {
 433     Node *n = useful.at(next++);
 434     if (n->is_SafePoint()) {
 435       // We're done with a parsing phase. Replaced nodes are not valid
 436       // beyond that point.
 437       n->as_SafePoint()->delete_replaced_nodes();
 438     }
 439     // Use raw traversal of out edges since this code removes out edges
 440     int max = n->outcnt();
 441     for (int j = 0; j < max; ++j) {
 442       Node* child = n->raw_out(j);
 443       if (!useful.member(child)) {
 444         assert(!child->is_top() || child != top(),
 445                "If top is cached in Compile object it is in useful list");
 446         // Only need to remove this out-edge to the useless node
 447         n->raw_del_out(j);
 448         --j;
 449         --max;
 450         if (child->is_data_proj_of_pure_function(n)) {
 451           worklist.push(n);
 452         }
 453       }
 454     }
 455     if (n->outcnt() == 1 && n->has_special_unique_user()) {
 456       assert(useful.member(n->unique_out()), "do not push a useless node");
 457       worklist.push(n->unique_out());
 458     }
 459   }
 460 
 461   remove_useless_nodes(_macro_nodes,        useful); // remove useless macro nodes
 462   remove_useless_nodes(_parse_predicates,   useful); // remove useless Parse Predicate nodes
 463   // Remove useless Template Assertion Predicate opaque nodes
 464   remove_useless_nodes(_template_assertion_predicate_opaques, useful);
 465   remove_useless_nodes(_expensive_nodes,    useful); // remove useless expensive nodes
 466   remove_useless_nodes(_reachability_fences, useful); // remove useless node recorded for post loop opts IGVN pass
 467   remove_useless_nodes(_for_post_loop_igvn, useful); // remove useless node recorded for post loop opts IGVN pass
 468   remove_useless_nodes(_for_merge_stores_igvn, useful); // remove useless node recorded for merge stores IGVN pass
 469   remove_useless_unstable_if_traps(useful);          // remove useless unstable_if traps
 470   remove_useless_coarsened_locks(useful);            // remove useless coarsened locks nodes
 471 #ifdef ASSERT
 472   if (_modified_nodes != nullptr) {
 473     _modified_nodes->remove_useless_nodes(useful.member_set());
 474   }
 475 #endif
 476 
 477   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 478   bs->eliminate_useless_gc_barriers(useful, this);
 479   // clean up the late inline lists
 480   remove_useless_late_inlines(                &_late_inlines, useful);
 481   remove_useless_late_inlines(         &_string_late_inlines, useful);
 482   remove_useless_late_inlines(         &_boxing_late_inlines, useful);
 483   remove_useless_late_inlines(&_vector_reboxing_late_inlines, useful);
 484   DEBUG_ONLY(verify_graph_edges(true /*check for no_dead_code*/, root_and_safepoints);)
 485 }
 486 
 487 // ============================================================================
 488 //------------------------------CompileWrapper---------------------------------
 489 class CompileWrapper : public StackObj {
 490   Compile *const _compile;
 491  public:
 492   CompileWrapper(Compile* compile);
 493 
 494   ~CompileWrapper();
 495 };
 496 
 497 CompileWrapper::CompileWrapper(Compile* compile) : _compile(compile) {
 498   // the Compile* pointer is stored in the current ciEnv:
 499   ciEnv* env = compile->env();
 500   assert(env == ciEnv::current(), "must already be a ciEnv active");
 501   assert(env->compiler_data() == nullptr, "compile already active?");
 502   env->set_compiler_data(compile);
 503   assert(compile == Compile::current(), "sanity");
 504 
 505   compile->set_type_dict(nullptr);
 506   compile->set_clone_map(new Dict(cmpkey, hashkey, _compile->comp_arena()));
 507   compile->clone_map().set_clone_idx(0);
 508   compile->set_type_last_size(0);
 509   compile->set_last_tf(nullptr, nullptr);
 510   compile->set_indexSet_arena(nullptr);
 511   compile->set_indexSet_free_block_list(nullptr);
 512   compile->init_type_arena();
 513   Type::Initialize(compile);
 514   _compile->begin_method();
 515   _compile->clone_map().set_debug(_compile->has_method() && _compile->directive()->CloneMapDebugOption);
 516 }
 517 CompileWrapper::~CompileWrapper() {
 518   // simulate crash during compilation
 519   assert(CICrashAt < 0 || _compile->compile_id() != CICrashAt, "just as planned");
 520 
 521   _compile->end_method();
 522   _compile->env()->set_compiler_data(nullptr);
 523 }
 524 
 525 
 526 //----------------------------print_compile_messages---------------------------
 527 void Compile::print_compile_messages() {
 528 #ifndef PRODUCT
 529   // Check if recompiling
 530   if (!subsume_loads() && PrintOpto) {
 531     // Recompiling without allowing machine instructions to subsume loads
 532     tty->print_cr("*********************************************************");
 533     tty->print_cr("** Bailout: Recompile without subsuming loads          **");
 534     tty->print_cr("*********************************************************");
 535   }
 536   if ((do_escape_analysis() != DoEscapeAnalysis) && PrintOpto) {
 537     // Recompiling without escape analysis
 538     tty->print_cr("*********************************************************");
 539     tty->print_cr("** Bailout: Recompile without escape analysis          **");
 540     tty->print_cr("*********************************************************");
 541   }
 542   if (do_iterative_escape_analysis() != DoEscapeAnalysis && PrintOpto) {
 543     // Recompiling without iterative escape analysis
 544     tty->print_cr("*********************************************************");
 545     tty->print_cr("** Bailout: Recompile without iterative escape analysis**");
 546     tty->print_cr("*********************************************************");
 547   }
 548   if (do_reduce_allocation_merges() != ReduceAllocationMerges && PrintOpto) {
 549     // Recompiling without reducing allocation merges
 550     tty->print_cr("*********************************************************");
 551     tty->print_cr("** Bailout: Recompile without reduce allocation merges **");
 552     tty->print_cr("*********************************************************");
 553   }
 554   if ((eliminate_boxing() != EliminateAutoBox) && PrintOpto) {
 555     // Recompiling without boxing elimination
 556     tty->print_cr("*********************************************************");
 557     tty->print_cr("** Bailout: Recompile without boxing elimination       **");
 558     tty->print_cr("*********************************************************");
 559   }
 560   if ((do_locks_coarsening() != EliminateLocks) && PrintOpto) {
 561     // Recompiling without locks coarsening
 562     tty->print_cr("*********************************************************");
 563     tty->print_cr("** Bailout: Recompile without locks coarsening         **");
 564     tty->print_cr("*********************************************************");
 565   }
 566   if (env()->break_at_compile()) {
 567     // Open the debugger when compiling this method.
 568     tty->print("### Breaking when compiling: ");
 569     method()->print_short_name();
 570     tty->cr();
 571     BREAKPOINT;
 572   }
 573 
 574   if( PrintOpto ) {
 575     if (is_osr_compilation()) {
 576       tty->print("[OSR]%3d", _compile_id);
 577     } else {
 578       tty->print("%3d", _compile_id);
 579     }
 580   }
 581 #endif
 582 }
 583 
 584 #ifndef PRODUCT
 585 void Compile::print_phase(const char* phase_name) {
 586   tty->print_cr("%u.\t%s", ++_phase_counter, phase_name);
 587 }
 588 
 589 void Compile::print_ideal_ir(const char* compile_phase_name) const {
 590   // keep the following output all in one block
 591   // This output goes directly to the tty, not the compiler log.
 592   // To enable tools to match it up with the compilation activity,
 593   // be sure to tag this tty output with the compile ID.
 594 
 595   // Node dumping can cause a safepoint, which can break the tty lock.
 596   // Buffer all node dumps, so that all safepoints happen before we lock.
 597   ResourceMark rm;
 598   stringStream ss;
 599 
 600   if (_output == nullptr) {
 601     ss.print_cr("AFTER: %s", compile_phase_name);
 602     // Print out all nodes in ascending order of index.
 603     // It is important that we traverse both inputs and outputs of nodes,
 604     // so that we reach all nodes that are connected to Root.
 605     root()->dump_bfs(MaxNodeLimit, nullptr, "-+S$", &ss);
 606   } else {
 607     // Dump the node blockwise if we have a scheduling
 608     _output->print_scheduling(&ss);
 609   }
 610 
 611   // Check that the lock is not broken by a safepoint.
 612   NoSafepointVerifier nsv;
 613   ttyLocker ttyl;
 614   if (xtty != nullptr) {
 615     xtty->head("ideal compile_id='%d'%s compile_phase='%s'",
 616                compile_id(),
 617                is_osr_compilation() ? " compile_kind='osr'" : "",
 618                compile_phase_name);
 619   }
 620 
 621   tty->print("%s", ss.as_string());
 622 
 623   if (xtty != nullptr) {
 624     xtty->tail("ideal");
 625   }
 626 }
 627 #endif
 628 
 629 // ============================================================================
 630 //------------------------------Compile standard-------------------------------
 631 
 632 // Compile a method.  entry_bci is -1 for normal compilations and indicates
 633 // the continuation bci for on stack replacement.
 634 
 635 
 636 Compile::Compile(ciEnv* ci_env, ciMethod* target, int osr_bci,
 637                  Options options, DirectiveSet* directive)
 638     : Phase(Compiler),
 639       _compile_id(ci_env->compile_id()),
 640       _options(options),
 641       _method(target),
 642       _entry_bci(osr_bci),
 643       _ilt(nullptr),
 644       _stub_function(nullptr),
 645       _stub_name(nullptr),
 646       _stub_id(StubId::NO_STUBID),
 647       _stub_entry_point(nullptr),
 648       _max_node_limit(MaxNodeLimit),
 649       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 650       _post_loop_opts_phase(false),
 651       _merge_stores_phase(false),
 652       _allow_macro_nodes(true),
 653       _inlining_progress(false),
 654       _inlining_incrementally(false),
 655       _do_cleanup(false),
 656       _has_reserved_stack_access(target->has_reserved_stack_access()),
 657 #ifndef PRODUCT
 658       _igv_idx(0),
 659       _trace_opto_output(directive->TraceOptoOutputOption),
 660 #endif
 661       _clinit_barrier_on_entry(false),
 662       _stress_seed(0),
 663       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 664       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 665       _env(ci_env),
 666       _directive(directive),
 667       _log(ci_env->log()),
 668       _first_failure_details(nullptr),
 669       _intrinsics(comp_arena(), 0, 0, nullptr),
 670       _macro_nodes(comp_arena(), 8, 0, nullptr),
 671       _parse_predicates(comp_arena(), 8, 0, nullptr),
 672       _template_assertion_predicate_opaques(comp_arena(), 8, 0, nullptr),
 673       _expensive_nodes(comp_arena(), 8, 0, nullptr),
 674       _reachability_fences(comp_arena(), 8, 0, nullptr),
 675       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 676       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 677       _unstable_if_traps(comp_arena(), 8, 0, nullptr),
 678       _coarsened_locks(comp_arena(), 8, 0, nullptr),
 679       _congraph(nullptr),
 680       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 681       _unique(0),
 682       _dead_node_count(0),
 683       _dead_node_list(comp_arena()),
 684       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 685       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 686       _node_arena(&_node_arena_one),
 687       _mach_constant_base_node(nullptr),
 688       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 689       _initial_gvn(nullptr),
 690       _igvn_worklist(nullptr),
 691       _types(nullptr),
 692       _node_hash(nullptr),
 693       _late_inlines(comp_arena(), 2, 0, nullptr),
 694       _string_late_inlines(comp_arena(), 2, 0, nullptr),
 695       _boxing_late_inlines(comp_arena(), 2, 0, nullptr),
 696       _vector_reboxing_late_inlines(comp_arena(), 2, 0, nullptr),
 697       _late_inlines_pos(0),
 698       _has_mh_late_inlines(false),
 699       _oom(false),
 700       _replay_inline_data(nullptr),
 701       _inline_printer(this),
 702       _java_calls(0),
 703       _inner_loops(0),
 704       _FIRST_STACK_mask(comp_arena()),
 705       _interpreter_frame_size(0),
 706       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 707       _output(nullptr)
 708 #ifndef PRODUCT
 709       ,
 710       _in_dump_cnt(0)
 711 #endif
 712 {
 713   C = this;
 714   CompileWrapper cw(this);
 715 
 716   TraceTime t1("Total compilation time", &_t_totalCompilation, CITime, CITimeVerbose);
 717   TraceTime t2(nullptr, &_t_methodCompilation, CITime, false);
 718 
 719 #if defined(SUPPORT_ASSEMBLY) || defined(SUPPORT_ABSTRACT_ASSEMBLY)
 720   bool print_opto_assembly = directive->PrintOptoAssemblyOption;
 721   // We can always print a disassembly, either abstract (hex dump) or
 722   // with the help of a suitable hsdis library. Thus, we should not
 723   // couple print_assembly and print_opto_assembly controls.
 724   // But: always print opto and regular assembly on compile command 'print'.
 725   bool print_assembly = directive->PrintAssemblyOption;
 726   set_print_assembly(print_opto_assembly || print_assembly);
 727 #else
 728   set_print_assembly(false); // must initialize.
 729 #endif
 730 
 731 #ifndef PRODUCT
 732   set_parsed_irreducible_loop(false);
 733 #endif
 734 
 735   if (directive->ReplayInlineOption) {
 736     _replay_inline_data = ciReplay::load_inline_data(method(), entry_bci(), ci_env->comp_level());
 737   }
 738   set_print_inlining(directive->PrintInliningOption || PrintOptoInlining);
 739   set_print_intrinsics(directive->PrintIntrinsicsOption);
 740   set_has_irreducible_loop(true); // conservative until build_loop_tree() reset it
 741 
 742   if (ProfileTraps) {
 743     // Make sure the method being compiled gets its own MDO,
 744     // so we can at least track the decompile_count().
 745     method()->ensure_method_data();
 746   }
 747 
 748   if (StressLCM || StressGCM || StressIGVN || StressCCP ||
 749       StressIncrementalInlining || StressMacroExpansion ||
 750       StressMacroElimination || StressUnstableIfTraps ||
 751       StressBailout || StressLoopPeeling || StressCountedLoop) {
 752     initialize_stress_seed(directive);
 753   }
 754 
 755   Init(/*do_aliasing=*/ true);
 756 
 757   print_compile_messages();
 758 
 759   _ilt = InlineTree::build_inline_tree_root();
 760 
 761   // Even if NO memory addresses are used, MergeMem nodes must have at least 1 slice
 762   assert(num_alias_types() >= AliasIdxRaw, "");
 763 
 764 #define MINIMUM_NODE_HASH  1023
 765 
 766   // GVN that will be run immediately on new nodes
 767   uint estimated_size = method()->code_size()*4+64;
 768   estimated_size = (estimated_size < MINIMUM_NODE_HASH ? MINIMUM_NODE_HASH : estimated_size);
 769   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
 770   _types = new (comp_arena()) Type_Array(comp_arena());
 771   _node_hash = new (comp_arena()) NodeHash(comp_arena(), estimated_size);
 772   PhaseGVN gvn;
 773   set_initial_gvn(&gvn);
 774 
 775   { // Scope for timing the parser
 776     TracePhase tp(_t_parser);
 777 
 778     // Put top into the hash table ASAP.
 779     initial_gvn()->transform(top());
 780 
 781     // Set up tf(), start(), and find a CallGenerator.
 782     CallGenerator* cg = nullptr;
 783     if (is_osr_compilation()) {
 784       const TypeTuple *domain = StartOSRNode::osr_domain();
 785       const TypeTuple *range = TypeTuple::make_range(method()->signature());
 786       init_tf(TypeFunc::make(domain, range));
 787       StartNode* s = new StartOSRNode(root(), domain);
 788       initial_gvn()->set_type_bottom(s);
 789       verify_start(s);
 790       cg = CallGenerator::for_osr(method(), entry_bci());
 791     } else {
 792       // Normal case.
 793       init_tf(TypeFunc::make(method()));
 794       StartNode* s = new StartNode(root(), tf()->domain());
 795       initial_gvn()->set_type_bottom(s);
 796       verify_start(s);
 797       float past_uses = method()->interpreter_invocation_count();
 798       float expected_uses = past_uses;
 799       cg = CallGenerator::for_inline(method(), expected_uses);
 800     }
 801     if (failing())  return;
 802     if (cg == nullptr) {
 803       const char* reason = InlineTree::check_can_parse(method());
 804       assert(reason != nullptr, "expect reason for parse failure");
 805       stringStream ss;
 806       ss.print("cannot parse method: %s", reason);
 807       record_method_not_compilable(ss.as_string());
 808       return;
 809     }
 810 
 811     gvn.set_type(root(), root()->bottom_type());
 812 
 813     JVMState* jvms = build_start_state(start(), tf());
 814     if ((jvms = cg->generate(jvms)) == nullptr) {
 815       assert(failure_reason() != nullptr, "expect reason for parse failure");
 816       stringStream ss;
 817       ss.print("method parse failed: %s", failure_reason());
 818       record_method_not_compilable(ss.as_string() DEBUG_ONLY(COMMA true));
 819       return;
 820     }
 821     GraphKit kit(jvms);
 822 
 823     if (!kit.stopped()) {
 824       // Accept return values, and transfer control we know not where.
 825       // This is done by a special, unique ReturnNode bound to root.
 826       return_values(kit.jvms());
 827     }
 828 
 829     if (kit.has_exceptions()) {
 830       // Any exceptions that escape from this call must be rethrown
 831       // to whatever caller is dynamically above us on the stack.
 832       // This is done by a special, unique RethrowNode bound to root.
 833       rethrow_exceptions(kit.transfer_exceptions_into_jvms());
 834     }
 835 
 836     assert(IncrementalInline || (_late_inlines.length() == 0 && !has_mh_late_inlines()), "incremental inlining is off");
 837 
 838     if (_late_inlines.length() == 0 && !has_mh_late_inlines() && !failing() && has_stringbuilder()) {
 839       inline_string_calls(true);
 840     }
 841 
 842     if (failing())  return;
 843 
 844     // Remove clutter produced by parsing.
 845     if (!failing()) {
 846       ResourceMark rm;
 847       PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
 848     }
 849   }
 850 
 851   // Note:  Large methods are capped off in do_one_bytecode().
 852   if (failing())  return;
 853 
 854   // After parsing, node notes are no longer automagic.
 855   // They must be propagated by register_new_node_with_optimizer(),
 856   // clone(), or the like.
 857   set_default_node_notes(nullptr);
 858 
 859 #ifndef PRODUCT
 860   if (should_print_igv(1)) {
 861     _igv_printer->print_inlining();
 862   }
 863 #endif
 864 
 865   if (failing())  return;
 866   NOT_PRODUCT( verify_graph_edges(); )
 867 
 868   // Now optimize
 869   Optimize();
 870   if (failing())  return;
 871   NOT_PRODUCT( verify_graph_edges(); )
 872 
 873 #ifndef PRODUCT
 874   if (should_print_ideal()) {
 875     print_ideal_ir("PrintIdeal");
 876   }
 877 #endif
 878 
 879 #ifdef ASSERT
 880   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
 881   bs->verify_gc_barriers(this, BarrierSetC2::BeforeCodeGen);
 882 #endif
 883 
 884   // Dump compilation data to replay it.
 885   if (directive->DumpReplayOption) {
 886     env()->dump_replay_data(_compile_id);
 887   }
 888   if (directive->DumpInlineOption && (ilt() != nullptr)) {
 889     env()->dump_inline_data(_compile_id);
 890   }
 891 
 892   // Now that we know the size of all the monitors we can add a fixed slot
 893   // for the original deopt pc.
 894   int next_slot = fixed_slots() + (sizeof(address) / VMRegImpl::stack_slot_size);
 895   set_fixed_slots(next_slot);
 896 
 897   // Compute when to use implicit null checks. Used by matching trap based
 898   // nodes and NullCheck optimization.
 899   set_allowed_deopt_reasons();
 900 
 901   // Now generate code
 902   Code_Gen();
 903 }
 904 
 905 //------------------------------Compile----------------------------------------
 906 // Compile a runtime stub
 907 Compile::Compile(ciEnv* ci_env,
 908                  TypeFunc_generator generator,
 909                  address stub_function,
 910                  const char* stub_name,
 911                  StubId stub_id,
 912                  int is_fancy_jump,
 913                  bool pass_tls,
 914                  bool return_pc,
 915                  DirectiveSet* directive)
 916     : Phase(Compiler),
 917       _compile_id(0),
 918       _options(Options::for_runtime_stub()),
 919       _method(nullptr),
 920       _entry_bci(InvocationEntryBci),
 921       _stub_function(stub_function),
 922       _stub_name(stub_name),
 923       _stub_id(stub_id),
 924       _stub_entry_point(nullptr),
 925       _max_node_limit(MaxNodeLimit),
 926       _node_count_inlining_cutoff(NodeCountInliningCutoff),
 927       _post_loop_opts_phase(false),
 928       _merge_stores_phase(false),
 929       _allow_macro_nodes(true),
 930       _inlining_progress(false),
 931       _inlining_incrementally(false),
 932       _has_reserved_stack_access(false),
 933 #ifndef PRODUCT
 934       _igv_idx(0),
 935       _trace_opto_output(directive->TraceOptoOutputOption),
 936 #endif
 937       _clinit_barrier_on_entry(false),
 938       _stress_seed(0),
 939       _comp_arena(mtCompiler, Arena::Tag::tag_comp),
 940       _barrier_set_state(BarrierSet::barrier_set()->barrier_set_c2()->create_barrier_state(comp_arena())),
 941       _env(ci_env),
 942       _directive(directive),
 943       _log(ci_env->log()),
 944       _first_failure_details(nullptr),
 945       _reachability_fences(comp_arena(), 8, 0, nullptr),
 946       _for_post_loop_igvn(comp_arena(), 8, 0, nullptr),
 947       _for_merge_stores_igvn(comp_arena(), 8, 0, nullptr),
 948       _congraph(nullptr),
 949       NOT_PRODUCT(_igv_printer(nullptr) COMMA)
 950       _unique(0),
 951       _dead_node_count(0),
 952       _dead_node_list(comp_arena()),
 953       _node_arena_one(mtCompiler, Arena::Tag::tag_node),
 954       _node_arena_two(mtCompiler, Arena::Tag::tag_node),
 955       _node_arena(&_node_arena_one),
 956       _mach_constant_base_node(nullptr),
 957       _Compile_types(mtCompiler, Arena::Tag::tag_type),
 958       _initial_gvn(nullptr),
 959       _igvn_worklist(nullptr),
 960       _types(nullptr),
 961       _node_hash(nullptr),
 962       _has_mh_late_inlines(false),
 963       _oom(false),
 964       _replay_inline_data(nullptr),
 965       _inline_printer(this),
 966       _java_calls(0),
 967       _inner_loops(0),
 968       _FIRST_STACK_mask(comp_arena()),
 969       _interpreter_frame_size(0),
 970       _regmask_arena(mtCompiler, Arena::Tag::tag_regmask),
 971       _output(nullptr),
 972 #ifndef PRODUCT
 973       _in_dump_cnt(0),
 974 #endif
 975       _allowed_reasons(0) {
 976   C = this;
 977 
 978   // try to reuse an existing stub
 979   {
 980     BlobId blob_id = StubInfo::blob(_stub_id);
 981     CodeBlob* blob = AOTCodeCache::load_code_blob(AOTCodeEntry::C2Blob, blob_id);
 982     if (blob != nullptr) {
 983       RuntimeStub* rs = blob->as_runtime_stub();
 984       _stub_entry_point = rs->entry_point();
 985       return;
 986     }
 987   }
 988 
 989   TraceTime t1(nullptr, &_t_totalCompilation, CITime, false);
 990   TraceTime t2(nullptr, &_t_stubCompilation, CITime, false);
 991 
 992 #ifndef PRODUCT
 993   set_print_assembly(PrintFrameConverterAssembly);
 994   set_parsed_irreducible_loop(false);
 995 #else
 996   set_print_assembly(false); // Must initialize.
 997 #endif
 998   set_has_irreducible_loop(false); // no loops
 999 
1000   CompileWrapper cw(this);
1001   Init(/*do_aliasing=*/ false);
1002   init_tf((*generator)());
1003 
1004   _igvn_worklist = new (comp_arena()) Unique_Node_List(comp_arena());
1005   _types = new (comp_arena()) Type_Array(comp_arena());
1006   _node_hash = new (comp_arena()) NodeHash(comp_arena(), 255);
1007 
1008   if (StressLCM || StressGCM || StressBailout) {
1009     initialize_stress_seed(directive);
1010   }
1011 
1012   {
1013     PhaseGVN gvn;
1014     set_initial_gvn(&gvn);    // not significant, but GraphKit guys use it pervasively
1015     gvn.transform(top());
1016 
1017     GraphKit kit;
1018     kit.gen_stub(stub_function, stub_name, is_fancy_jump, pass_tls, return_pc);
1019   }
1020 
1021   NOT_PRODUCT( verify_graph_edges(); )
1022 
1023   Code_Gen();
1024 }
1025 
1026 Compile::~Compile() {
1027   delete _first_failure_details;
1028 };
1029 
1030 //------------------------------Init-------------------------------------------
1031 // Prepare for a single compilation
1032 void Compile::Init(bool aliasing) {
1033   _do_aliasing = aliasing;
1034   _unique  = 0;
1035   _regalloc = nullptr;
1036 
1037   _tf      = nullptr;  // filled in later
1038   _top     = nullptr;  // cached later
1039   _matcher = nullptr;  // filled in later
1040   _cfg     = nullptr;  // filled in later
1041 
1042   _node_note_array = nullptr;
1043   _default_node_notes = nullptr;
1044   DEBUG_ONLY( _modified_nodes = nullptr; ) // Used in Optimize()
1045 
1046   _immutable_memory = nullptr; // filled in at first inquiry
1047 
1048 #ifdef ASSERT
1049   _phase_optimize_finished = false;
1050   _phase_verify_ideal_loop = false;
1051   _exception_backedge = false;
1052   _type_verify = nullptr;
1053 #endif
1054 
1055   // Globally visible Nodes
1056   // First set TOP to null to give safe behavior during creation of RootNode
1057   set_cached_top_node(nullptr);
1058   set_root(new RootNode());
1059   // Now that you have a Root to point to, create the real TOP
1060   set_cached_top_node( new ConNode(Type::TOP) );
1061   set_recent_alloc(nullptr, nullptr);
1062 
1063   // Create Debug Information Recorder to record scopes, oopmaps, etc.
1064   env()->set_oop_recorder(new OopRecorder(env()->arena()));
1065   env()->set_debug_info(new DebugInformationRecorder(env()->oop_recorder()));
1066   env()->set_dependencies(new Dependencies(env()));
1067 
1068   _fixed_slots = 0;
1069   set_has_split_ifs(false);
1070   set_has_loops(false); // first approximation
1071   set_has_stringbuilder(false);
1072   set_has_boxed_value(false);
1073   _trap_can_recompile = false;  // no traps emitted yet
1074   _major_progress = true; // start out assuming good things will happen
1075   set_has_unsafe_access(false);
1076   set_max_vector_size(0);
1077   set_clear_upper_avx(false);  //false as default for clear upper bits of ymm registers
1078   Copy::zero_to_bytes(_trap_hist, sizeof(_trap_hist));
1079   set_decompile_count(0);
1080 
1081 #ifndef PRODUCT
1082   _phase_counter = 0;
1083   Copy::zero_to_bytes(_igv_phase_iter, sizeof(_igv_phase_iter));
1084 #endif
1085 
1086   set_do_freq_based_layout(_directive->BlockLayoutByFrequencyOption);
1087   _loop_opts_cnt = LoopOptsCount;
1088   set_do_inlining(Inline);
1089   set_max_inline_size(MaxInlineSize);
1090   set_freq_inline_size(FreqInlineSize);
1091   set_do_scheduling(OptoScheduling);
1092 
1093   set_do_vector_loop(false);
1094   set_has_monitors(false);
1095   set_has_scoped_access(false);
1096 
1097   if (AllowVectorizeOnDemand) {
1098     if (has_method() && _directive->VectorizeOption) {
1099       set_do_vector_loop(true);
1100       NOT_PRODUCT(if (do_vector_loop() && Verbose) {tty->print("Compile::Init: do vectorized loops (SIMD like) for method %s\n",  method()->name()->as_quoted_ascii());})
1101     } else if (has_method() && method()->name() != nullptr &&
1102                method()->intrinsic_id() == vmIntrinsics::_forEachRemaining) {
1103       set_do_vector_loop(true);
1104     }
1105   }
1106   set_use_cmove(UseCMoveUnconditionally /* || do_vector_loop()*/); //TODO: consider do_vector_loop() mandate use_cmove unconditionally
1107   NOT_PRODUCT(if (use_cmove() && Verbose && has_method()) {tty->print("Compile::Init: use CMove without profitability tests for method %s\n",  method()->name()->as_quoted_ascii());})
1108 
1109   _max_node_limit = _directive->MaxNodeLimitOption;
1110 
1111   if (VM_Version::supports_fast_class_init_checks() && has_method() && !is_osr_compilation() && method()->needs_clinit_barrier()) {
1112     set_clinit_barrier_on_entry(true);
1113   }
1114   if (debug_info()->recording_non_safepoints()) {
1115     set_node_note_array(new(comp_arena()) GrowableArray<Node_Notes*>
1116                         (comp_arena(), 8, 0, nullptr));
1117     set_default_node_notes(Node_Notes::make(this));
1118   }
1119 
1120   const int grow_ats = 16;
1121   _max_alias_types = grow_ats;
1122   _alias_types   = NEW_ARENA_ARRAY(comp_arena(), AliasType*, grow_ats);
1123   AliasType* ats = NEW_ARENA_ARRAY(comp_arena(), AliasType,  grow_ats);
1124   Copy::zero_to_bytes(ats, sizeof(AliasType)*grow_ats);
1125   {
1126     for (int i = 0; i < grow_ats; i++)  _alias_types[i] = &ats[i];
1127   }
1128   // Initialize the first few types.
1129   _alias_types[AliasIdxTop]->Init(AliasIdxTop, nullptr);
1130   _alias_types[AliasIdxBot]->Init(AliasIdxBot, TypePtr::BOTTOM);
1131   _alias_types[AliasIdxRaw]->Init(AliasIdxRaw, TypeRawPtr::BOTTOM);
1132   _num_alias_types = AliasIdxRaw+1;
1133   // Zero out the alias type cache.
1134   Copy::zero_to_bytes(_alias_cache, sizeof(_alias_cache));
1135   // A null adr_type hits in the cache right away.  Preload the right answer.
1136   probe_alias_cache(nullptr)->_index = AliasIdxTop;
1137 }
1138 
1139 #ifdef ASSERT
1140 // Verify that the current StartNode is valid.
1141 void Compile::verify_start(StartNode* s) const {
1142   assert(failing_internal() || s == start(), "should be StartNode");
1143 }
1144 #endif
1145 
1146 /**
1147  * Return the 'StartNode'. We must not have a pending failure, since the ideal graph
1148  * can be in an inconsistent state, i.e., we can get segmentation faults when traversing
1149  * the ideal graph.
1150  */
1151 StartNode* Compile::start() const {
1152   assert (!failing_internal() || C->failure_is_artificial(), "Must not have pending failure. Reason is: %s", failure_reason());
1153   for (DUIterator_Fast imax, i = root()->fast_outs(imax); i < imax; i++) {
1154     Node* start = root()->fast_out(i);
1155     if (start->is_Start()) {
1156       return start->as_Start();
1157     }
1158   }
1159   fatal("Did not find Start node!");
1160   return nullptr;
1161 }
1162 
1163 //-------------------------------immutable_memory-------------------------------------
1164 // Access immutable memory
1165 Node* Compile::immutable_memory() {
1166   if (_immutable_memory != nullptr) {
1167     return _immutable_memory;
1168   }
1169   StartNode* s = start();
1170   for (DUIterator_Fast imax, i = s->fast_outs(imax); true; i++) {
1171     Node *p = s->fast_out(i);
1172     if (p != s && p->as_Proj()->_con == TypeFunc::Memory) {
1173       _immutable_memory = p;
1174       return _immutable_memory;
1175     }
1176   }
1177   ShouldNotReachHere();
1178   return nullptr;
1179 }
1180 
1181 //----------------------set_cached_top_node------------------------------------
1182 // Install the cached top node, and make sure Node::is_top works correctly.
1183 void Compile::set_cached_top_node(Node* tn) {
1184   if (tn != nullptr)  verify_top(tn);
1185   Node* old_top = _top;
1186   _top = tn;
1187   // Calling Node::setup_is_top allows the nodes the chance to adjust
1188   // their _out arrays.
1189   if (_top != nullptr)     _top->setup_is_top();
1190   if (old_top != nullptr)  old_top->setup_is_top();
1191   assert(_top == nullptr || top()->is_top(), "");
1192 }
1193 
1194 #ifdef ASSERT
1195 uint Compile::count_live_nodes_by_graph_walk() {
1196   Unique_Node_List useful(comp_arena());
1197   // Get useful node list by walking the graph.
1198   identify_useful_nodes(useful);
1199   return useful.size();
1200 }
1201 
1202 void Compile::print_missing_nodes() {
1203 
1204   // Return if CompileLog is null and PrintIdealNodeCount is false.
1205   if ((_log == nullptr) && (! PrintIdealNodeCount)) {
1206     return;
1207   }
1208 
1209   // This is an expensive function. It is executed only when the user
1210   // specifies VerifyIdealNodeCount option or otherwise knows the
1211   // additional work that needs to be done to identify reachable nodes
1212   // by walking the flow graph and find the missing ones using
1213   // _dead_node_list.
1214 
1215   Unique_Node_List useful(comp_arena());
1216   // Get useful node list by walking the graph.
1217   identify_useful_nodes(useful);
1218 
1219   uint l_nodes = C->live_nodes();
1220   uint l_nodes_by_walk = useful.size();
1221 
1222   if (l_nodes != l_nodes_by_walk) {
1223     if (_log != nullptr) {
1224       _log->begin_head("mismatched_nodes count='%d'", abs((int) (l_nodes - l_nodes_by_walk)));
1225       _log->stamp();
1226       _log->end_head();
1227     }
1228     VectorSet& useful_member_set = useful.member_set();
1229     int last_idx = l_nodes_by_walk;
1230     for (int i = 0; i < last_idx; i++) {
1231       if (useful_member_set.test(i)) {
1232         if (_dead_node_list.test(i)) {
1233           if (_log != nullptr) {
1234             _log->elem("mismatched_node_info node_idx='%d' type='both live and dead'", i);
1235           }
1236           if (PrintIdealNodeCount) {
1237             // Print the log message to tty
1238               tty->print_cr("mismatched_node idx='%d' both live and dead'", i);
1239               useful.at(i)->dump();
1240           }
1241         }
1242       }
1243       else if (! _dead_node_list.test(i)) {
1244         if (_log != nullptr) {
1245           _log->elem("mismatched_node_info node_idx='%d' type='neither live nor dead'", i);
1246         }
1247         if (PrintIdealNodeCount) {
1248           // Print the log message to tty
1249           tty->print_cr("mismatched_node idx='%d' type='neither live nor dead'", i);
1250         }
1251       }
1252     }
1253     if (_log != nullptr) {
1254       _log->tail("mismatched_nodes");
1255     }
1256   }
1257 }
1258 void Compile::record_modified_node(Node* n) {
1259   if (_modified_nodes != nullptr && !_inlining_incrementally && !n->is_Con()) {
1260     _modified_nodes->push(n);
1261   }
1262 }
1263 
1264 void Compile::remove_modified_node(Node* n) {
1265   if (_modified_nodes != nullptr) {
1266     _modified_nodes->remove(n);
1267   }
1268 }
1269 #endif
1270 
1271 #ifndef PRODUCT
1272 void Compile::verify_top(Node* tn) const {
1273   if (tn != nullptr) {
1274     assert(tn->is_Con(), "top node must be a constant");
1275     assert(((ConNode*)tn)->type() == Type::TOP, "top node must have correct type");
1276     assert(tn->in(0) != nullptr, "must have live top node");
1277   }
1278 }
1279 #endif
1280 
1281 
1282 ///-------------------Managing Per-Node Debug & Profile Info-------------------
1283 
1284 void Compile::grow_node_notes(GrowableArray<Node_Notes*>* arr, int grow_by) {
1285   guarantee(arr != nullptr, "");
1286   int num_blocks = arr->length();
1287   if (grow_by < num_blocks)  grow_by = num_blocks;
1288   int num_notes = grow_by * _node_notes_block_size;
1289   Node_Notes* notes = NEW_ARENA_ARRAY(node_arena(), Node_Notes, num_notes);
1290   Copy::zero_to_bytes(notes, num_notes * sizeof(Node_Notes));
1291   while (num_notes > 0) {
1292     arr->append(notes);
1293     notes     += _node_notes_block_size;
1294     num_notes -= _node_notes_block_size;
1295   }
1296   assert(num_notes == 0, "exact multiple, please");
1297 }
1298 
1299 bool Compile::copy_node_notes_to(Node* dest, Node* source) {
1300   if (source == nullptr || dest == nullptr)  return false;
1301 
1302   if (dest->is_Con())
1303     return false;               // Do not push debug info onto constants.
1304 
1305 #ifdef ASSERT
1306   // Leave a bread crumb trail pointing to the original node:
1307   if (dest != nullptr && dest != source && dest->debug_orig() == nullptr) {
1308     dest->set_debug_orig(source);
1309   }
1310 #endif
1311 
1312   if (node_note_array() == nullptr)
1313     return false;               // Not collecting any notes now.
1314 
1315   // This is a copy onto a pre-existing node, which may already have notes.
1316   // If both nodes have notes, do not overwrite any pre-existing notes.
1317   Node_Notes* source_notes = node_notes_at(source->_idx);
1318   if (source_notes == nullptr || source_notes->is_clear())  return false;
1319   Node_Notes* dest_notes   = node_notes_at(dest->_idx);
1320   if (dest_notes == nullptr || dest_notes->is_clear()) {
1321     return set_node_notes_at(dest->_idx, source_notes);
1322   }
1323 
1324   Node_Notes merged_notes = (*source_notes);
1325   // The order of operations here ensures that dest notes will win...
1326   merged_notes.update_from(dest_notes);
1327   return set_node_notes_at(dest->_idx, &merged_notes);
1328 }
1329 
1330 
1331 //--------------------------allow_range_check_smearing-------------------------
1332 // Gating condition for coalescing similar range checks.
1333 // Sometimes we try 'speculatively' replacing a series of a range checks by a
1334 // single covering check that is at least as strong as any of them.
1335 // If the optimization succeeds, the simplified (strengthened) range check
1336 // will always succeed.  If it fails, we will deopt, and then give up
1337 // on the optimization.
1338 bool Compile::allow_range_check_smearing() const {
1339   // If this method has already thrown a range-check,
1340   // assume it was because we already tried range smearing
1341   // and it failed.
1342   uint already_trapped = trap_count(Deoptimization::Reason_range_check);
1343   return !already_trapped;
1344 }
1345 
1346 
1347 //------------------------------flatten_alias_type-----------------------------
1348 const TypePtr *Compile::flatten_alias_type( const TypePtr *tj ) const {
1349   assert(do_aliasing(), "Aliasing should be enabled");
1350   int offset = tj->offset();
1351   TypePtr::PTR ptr = tj->ptr();
1352 
1353   // Known instance (scalarizable allocation) alias only with itself.
1354   bool is_known_inst = tj->isa_oopptr() != nullptr &&
1355                        tj->is_oopptr()->is_known_instance();
1356 
1357   // Process weird unsafe references.
1358   if (offset == Type::OffsetBot && (tj->isa_instptr() /*|| tj->isa_klassptr()*/)) {
1359     assert(InlineUnsafeOps || StressReflectiveCode, "indeterminate pointers come only from unsafe ops");
1360     assert(!is_known_inst, "scalarizable allocation should not have unsafe references");
1361     tj = TypeOopPtr::BOTTOM;
1362     ptr = tj->ptr();
1363     offset = tj->offset();
1364   }
1365 
1366   // Array pointers need some flattening
1367   const TypeAryPtr* ta = tj->isa_aryptr();
1368   if (ta && ta->is_stable()) {
1369     // Erase stability property for alias analysis.
1370     tj = ta = ta->cast_to_stable(false);
1371   }
1372   if( ta && is_known_inst ) {
1373     if ( offset != Type::OffsetBot &&
1374          offset > arrayOopDesc::length_offset_in_bytes() ) {
1375       offset = Type::OffsetBot; // Flatten constant access into array body only
1376       tj = ta = ta->
1377               remove_speculative()->
1378               cast_to_ptr_type(ptr)->
1379               with_offset(offset);
1380     }
1381   } else if (ta != nullptr) {
1382     // Common slices
1383     if (offset == arrayOopDesc::length_offset_in_bytes()) {
1384       return TypeAryPtr::RANGE;
1385     } else if (offset == oopDesc::klass_offset_in_bytes()) {
1386       return TypeInstPtr::KLASS;
1387     } else if (offset == oopDesc::mark_offset_in_bytes()) {
1388       return TypeInstPtr::MARK;
1389     }
1390 
1391     // Remove size and stability
1392     const TypeAry* normalized_ary = TypeAry::make(ta->elem(), TypeInt::POS, false);
1393     // Remove ptr, const_oop, and offset
1394     if (ta->elem() == Type::BOTTOM) {
1395       // Bottom array (meet of int[] and byte[] for example), accesses to it will be done with
1396       // Unsafe. This should alias with all arrays. For now just leave it as it is (this is
1397       // incorrect, see JDK-8331133).
1398       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, nullptr, false, Type::OffsetBot);
1399     } else if (ta->elem()->make_oopptr() != nullptr) {
1400       // Object arrays, all of them share the same slice
1401       const TypeAry* tary = TypeAry::make(TypeInstPtr::BOTTOM, TypeInt::POS, false);
1402       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, tary, nullptr, false, Type::OffsetBot);
1403     } else {
1404       // Primitive arrays
1405       tj = ta = TypeAryPtr::make(TypePtr::BotPTR, nullptr, normalized_ary, ta->exact_klass(), true, Type::OffsetBot);
1406     }
1407 
1408     // Arrays of bytes and of booleans both use 'bastore' and 'baload' so
1409     // cannot be distinguished by bytecode alone.
1410     if (ta->elem() == TypeInt::BOOL) {
1411       tj = ta = TypeAryPtr::BYTES;
1412     }
1413   }
1414 
1415   // Oop pointers need some flattening
1416   const TypeInstPtr *to = tj->isa_instptr();
1417   if (to && to != TypeOopPtr::BOTTOM) {
1418     ciInstanceKlass* ik = to->instance_klass();
1419     if( ptr == TypePtr::Constant ) {
1420       if (ik != ciEnv::current()->Class_klass() ||
1421           offset < ik->layout_helper_size_in_bytes()) {
1422         // No constant oop pointers (such as Strings); they alias with
1423         // unknown strings.
1424         assert(!is_known_inst, "not scalarizable allocation");
1425         tj = to = to->
1426                 cast_to_instance_id(TypeOopPtr::InstanceBot)->
1427                 remove_speculative()->
1428                 cast_to_ptr_type(TypePtr::BotPTR)->
1429                 cast_to_exactness(false);
1430       }
1431     } else if( is_known_inst ) {
1432       tj = to; // Keep NotNull and klass_is_exact for instance type
1433     } else if( ptr == TypePtr::NotNull || to->klass_is_exact() ) {
1434       // During the 2nd round of IterGVN, NotNull castings are removed.
1435       // Make sure the Bottom and NotNull variants alias the same.
1436       // Also, make sure exact and non-exact variants alias the same.
1437       tj = to = to->
1438               remove_speculative()->
1439               cast_to_instance_id(TypeOopPtr::InstanceBot)->
1440               cast_to_ptr_type(TypePtr::BotPTR)->
1441               cast_to_exactness(false);
1442     }
1443     if (to->speculative() != nullptr) {
1444       tj = to = to->remove_speculative();
1445     }
1446     // Canonicalize the holder of this field
1447     if (offset >= 0 && offset < instanceOopDesc::base_offset_in_bytes()) {
1448       // First handle header references such as a LoadKlassNode, even if the
1449       // object's klass is unloaded at compile time (4965979).
1450       if (!is_known_inst) { // Do it only for non-instance types
1451         tj = to = TypeInstPtr::make(TypePtr::BotPTR, env()->Object_klass(), false, nullptr, offset);
1452       }
1453     } else if (offset < 0 || offset >= ik->layout_helper_size_in_bytes()) {
1454       // Static fields are in the space above the normal instance
1455       // fields in the java.lang.Class instance.
1456       if (ik != ciEnv::current()->Class_klass()) {
1457         to = nullptr;
1458         tj = TypeOopPtr::BOTTOM;
1459         offset = tj->offset();
1460       }
1461     } else {
1462       ciInstanceKlass *canonical_holder = ik->get_canonical_holder(offset);
1463       assert(offset < canonical_holder->layout_helper_size_in_bytes(), "");
1464       assert(tj->offset() == offset, "no change to offset expected");
1465       bool xk = to->klass_is_exact();
1466       int instance_id = to->instance_id();
1467 
1468       // If the input type's class is the holder: if exact, the type only includes interfaces implemented by the holder
1469       // but if not exact, it may include extra interfaces: build new type from the holder class to make sure only
1470       // its interfaces are included.
1471       if (xk && ik->equals(canonical_holder)) {
1472         assert(tj == TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id), "exact type should be canonical type");
1473       } else {
1474         assert(xk || !is_known_inst, "Known instance should be exact type");
1475         tj = to = TypeInstPtr::make(to->ptr(), canonical_holder, is_known_inst, nullptr, offset, instance_id);
1476       }
1477     }
1478   }
1479 
1480   // Klass pointers to object array klasses need some flattening
1481   const TypeKlassPtr *tk = tj->isa_klassptr();
1482   if( tk ) {
1483     // If we are referencing a field within a Klass, we need
1484     // to assume the worst case of an Object.  Both exact and
1485     // inexact types must flatten to the same alias class so
1486     // use NotNull as the PTR.
1487     if ( offset == Type::OffsetBot || (offset >= 0 && (size_t)offset < sizeof(Klass)) ) {
1488       tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull,
1489                                        env()->Object_klass(),
1490                                        offset);
1491     }
1492 
1493     if (tk->isa_aryklassptr() && tk->is_aryklassptr()->elem()->isa_klassptr()) {
1494       ciKlass* k = ciObjArrayKlass::make(env()->Object_klass());
1495       if (!k || !k->is_loaded()) {                  // Only fails for some -Xcomp runs
1496         tj = tk = TypeInstKlassPtr::make(TypePtr::NotNull, env()->Object_klass(), offset);
1497       } else {
1498         tj = tk = TypeAryKlassPtr::make(TypePtr::NotNull, tk->is_aryklassptr()->elem(), k, offset);
1499       }
1500     }
1501 
1502     // Check for precise loads from the primary supertype array and force them
1503     // to the supertype cache alias index.  Check for generic array loads from
1504     // the primary supertype array and also force them to the supertype cache
1505     // alias index.  Since the same load can reach both, we need to merge
1506     // these 2 disparate memories into the same alias class.  Since the
1507     // primary supertype array is read-only, there's no chance of confusion
1508     // where we bypass an array load and an array store.
1509     int primary_supers_offset = in_bytes(Klass::primary_supers_offset());
1510     if (offset == Type::OffsetBot ||
1511         (offset >= primary_supers_offset &&
1512          offset < (int)(primary_supers_offset + Klass::primary_super_limit() * wordSize)) ||
1513         offset == (int)in_bytes(Klass::secondary_super_cache_offset())) {
1514       offset = in_bytes(Klass::secondary_super_cache_offset());
1515       tj = tk = tk->with_offset(offset);
1516     }
1517   }
1518 
1519   // Flatten all Raw pointers together.
1520   if (tj->base() == Type::RawPtr)
1521     tj = TypeRawPtr::BOTTOM;
1522 
1523   if (tj->base() == Type::AnyPtr)
1524     tj = TypePtr::BOTTOM;      // An error, which the caller must check for.
1525 
1526   offset = tj->offset();
1527   assert( offset != Type::OffsetTop, "Offset has fallen from constant" );
1528 
1529   assert( (offset != Type::OffsetBot && tj->base() != Type::AryPtr) ||
1530           (offset == Type::OffsetBot && tj->base() == Type::AryPtr) ||
1531           (offset == Type::OffsetBot && tj == TypeOopPtr::BOTTOM) ||
1532           (offset == Type::OffsetBot && tj == TypePtr::BOTTOM) ||
1533           (offset == oopDesc::mark_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1534           (offset == oopDesc::klass_offset_in_bytes() && tj->base() == Type::AryPtr) ||
1535           (offset == arrayOopDesc::length_offset_in_bytes() && tj->base() == Type::AryPtr),
1536           "For oops, klasses, raw offset must be constant; for arrays the offset is never known" );
1537   assert( tj->ptr() != TypePtr::TopPTR &&
1538           tj->ptr() != TypePtr::AnyNull &&
1539           tj->ptr() != TypePtr::Null, "No imprecise addresses" );
1540 //    assert( tj->ptr() != TypePtr::Constant ||
1541 //            tj->base() == Type::RawPtr ||
1542 //            tj->base() == Type::KlassPtr, "No constant oop addresses" );
1543 
1544   return tj;
1545 }
1546 
1547 void Compile::AliasType::Init(int i, const TypePtr* at) {
1548   assert(AliasIdxTop <= i && i < Compile::current()->_max_alias_types, "Invalid alias index");
1549   _index = i;
1550   _adr_type = at;
1551   _field = nullptr;
1552   _element = nullptr;
1553   _is_rewritable = true; // default
1554   const TypeOopPtr *atoop = (at != nullptr) ? at->isa_oopptr() : nullptr;
1555   if (atoop != nullptr && atoop->is_known_instance()) {
1556     const TypeOopPtr *gt = atoop->cast_to_instance_id(TypeOopPtr::InstanceBot);
1557     _general_index = Compile::current()->get_alias_index(gt);
1558   } else {
1559     _general_index = 0;
1560   }
1561 }
1562 
1563 BasicType Compile::AliasType::basic_type() const {
1564   if (element() != nullptr) {
1565     const Type* element = adr_type()->is_aryptr()->elem();
1566     return element->isa_narrowoop() ? T_OBJECT : element->array_element_basic_type();
1567   } if (field() != nullptr) {
1568     return field()->layout_type();
1569   } else {
1570     return T_ILLEGAL; // unknown
1571   }
1572 }
1573 
1574 //---------------------------------print_on------------------------------------
1575 #ifndef PRODUCT
1576 void Compile::AliasType::print_on(outputStream* st) {
1577   if (index() < 10)
1578         st->print("@ <%d> ", index());
1579   else  st->print("@ <%d>",  index());
1580   st->print(is_rewritable() ? "   " : " RO");
1581   int offset = adr_type()->offset();
1582   if (offset == Type::OffsetBot)
1583         st->print(" +any");
1584   else  st->print(" +%-3d", offset);
1585   st->print(" in ");
1586   adr_type()->dump_on(st);
1587   const TypeOopPtr* tjp = adr_type()->isa_oopptr();
1588   if (field() != nullptr && tjp) {
1589     if (tjp->is_instptr()->instance_klass()  != field()->holder() ||
1590         tjp->offset() != field()->offset_in_bytes()) {
1591       st->print(" != ");
1592       field()->print();
1593       st->print(" ***");
1594     }
1595   }
1596 }
1597 
1598 void print_alias_types() {
1599   Compile* C = Compile::current();
1600   tty->print_cr("--- Alias types, AliasIdxBot .. %d", C->num_alias_types()-1);
1601   for (int idx = Compile::AliasIdxBot; idx < C->num_alias_types(); idx++) {
1602     C->alias_type(idx)->print_on(tty);
1603     tty->cr();
1604   }
1605 }
1606 #endif
1607 
1608 
1609 //----------------------------probe_alias_cache--------------------------------
1610 Compile::AliasCacheEntry* Compile::probe_alias_cache(const TypePtr* adr_type) {
1611   intptr_t key = (intptr_t) adr_type;
1612   key ^= key >> logAliasCacheSize;
1613   return &_alias_cache[key & right_n_bits(logAliasCacheSize)];
1614 }
1615 
1616 
1617 //-----------------------------grow_alias_types--------------------------------
1618 void Compile::grow_alias_types() {
1619   const int old_ats  = _max_alias_types; // how many before?
1620   const int new_ats  = old_ats;          // how many more?
1621   const int grow_ats = old_ats+new_ats;  // how many now?
1622   _max_alias_types = grow_ats;
1623   _alias_types =  REALLOC_ARENA_ARRAY(comp_arena(), _alias_types, old_ats, grow_ats);
1624   AliasType* ats =    NEW_ARENA_ARRAY(comp_arena(), AliasType, new_ats);
1625   Copy::zero_to_bytes(ats, sizeof(AliasType)*new_ats);
1626   for (int i = 0; i < new_ats; i++)  _alias_types[old_ats+i] = &ats[i];
1627 }
1628 
1629 
1630 //--------------------------------find_alias_type------------------------------
1631 Compile::AliasType* Compile::find_alias_type(const TypePtr* adr_type, bool no_create, ciField* original_field) {
1632   if (!do_aliasing()) {
1633     return alias_type(AliasIdxBot);
1634   }
1635 
1636   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1637   if (ace->_adr_type == adr_type) {
1638     return alias_type(ace->_index);
1639   }
1640 
1641   // Handle special cases.
1642   if (adr_type == nullptr)          return alias_type(AliasIdxTop);
1643   if (adr_type == TypePtr::BOTTOM)  return alias_type(AliasIdxBot);
1644 
1645   // Do it the slow way.
1646   const TypePtr* flat = flatten_alias_type(adr_type);
1647 
1648 #ifdef ASSERT
1649   {
1650     ResourceMark rm;
1651     assert(flat == flatten_alias_type(flat), "not idempotent: adr_type = %s; flat = %s => %s",
1652            Type::str(adr_type), Type::str(flat), Type::str(flatten_alias_type(flat)));
1653     assert(flat != TypePtr::BOTTOM, "cannot alias-analyze an untyped ptr: adr_type = %s",
1654            Type::str(adr_type));
1655     if (flat->isa_oopptr() && !flat->isa_klassptr()) {
1656       const TypeOopPtr* foop = flat->is_oopptr();
1657       // Scalarizable allocations have exact klass always.
1658       bool exact = !foop->klass_is_exact() || foop->is_known_instance();
1659       const TypePtr* xoop = foop->cast_to_exactness(exact)->is_ptr();
1660       assert(foop == flatten_alias_type(xoop), "exactness must not affect alias type: foop = %s; xoop = %s",
1661              Type::str(foop), Type::str(xoop));
1662     }
1663   }
1664 #endif
1665 
1666   int idx = AliasIdxTop;
1667   for (int i = 0; i < num_alias_types(); i++) {
1668     if (alias_type(i)->adr_type() == flat) {
1669       idx = i;
1670       break;
1671     }
1672   }
1673 
1674   if (idx == AliasIdxTop) {
1675     if (no_create)  return nullptr;
1676     // Grow the array if necessary.
1677     if (_num_alias_types == _max_alias_types)  grow_alias_types();
1678     // Add a new alias type.
1679     idx = _num_alias_types++;
1680     _alias_types[idx]->Init(idx, flat);
1681     if (flat == TypeInstPtr::KLASS)  alias_type(idx)->set_rewritable(false);
1682     if (flat == TypeAryPtr::RANGE)   alias_type(idx)->set_rewritable(false);
1683     if (flat->isa_instptr()) {
1684       if (flat->offset() == java_lang_Class::klass_offset()
1685           && flat->is_instptr()->instance_klass() == env()->Class_klass())
1686         alias_type(idx)->set_rewritable(false);
1687     }
1688     if (flat->isa_aryptr()) {
1689 #ifdef ASSERT
1690       const int header_size_min  = arrayOopDesc::base_offset_in_bytes(T_BYTE);
1691       // (T_BYTE has the weakest alignment and size restrictions...)
1692       assert(flat->offset() < header_size_min, "array body reference must be OffsetBot");
1693 #endif
1694       if (flat->offset() == TypePtr::OffsetBot) {
1695         alias_type(idx)->set_element(flat->is_aryptr()->elem());
1696       }
1697     }
1698     if (flat->isa_klassptr()) {
1699       if (UseCompactObjectHeaders) {
1700         if (flat->offset() == in_bytes(Klass::prototype_header_offset()))
1701           alias_type(idx)->set_rewritable(false);
1702       }
1703       if (flat->offset() == in_bytes(Klass::super_check_offset_offset()))
1704         alias_type(idx)->set_rewritable(false);
1705       if (flat->offset() == in_bytes(Klass::misc_flags_offset()))
1706         alias_type(idx)->set_rewritable(false);
1707       if (flat->offset() == in_bytes(Klass::java_mirror_offset()))
1708         alias_type(idx)->set_rewritable(false);
1709       if (flat->offset() == in_bytes(Klass::secondary_super_cache_offset()))
1710         alias_type(idx)->set_rewritable(false);
1711     }
1712 
1713     if (flat->isa_instklassptr()) {
1714       if (flat->offset() == in_bytes(InstanceKlass::access_flags_offset())) {
1715         alias_type(idx)->set_rewritable(false);
1716       }
1717     }
1718     // %%% (We would like to finalize JavaThread::threadObj_offset(),
1719     // but the base pointer type is not distinctive enough to identify
1720     // references into JavaThread.)
1721 
1722     // Check for final fields.
1723     const TypeInstPtr* tinst = flat->isa_instptr();
1724     if (tinst && tinst->offset() >= instanceOopDesc::base_offset_in_bytes()) {
1725       ciField* field;
1726       if (tinst->const_oop() != nullptr &&
1727           tinst->instance_klass() == ciEnv::current()->Class_klass() &&
1728           tinst->offset() >= (tinst->instance_klass()->layout_helper_size_in_bytes())) {
1729         // static field
1730         ciInstanceKlass* k = tinst->const_oop()->as_instance()->java_lang_Class_klass()->as_instance_klass();
1731         field = k->get_field_by_offset(tinst->offset(), true);
1732       } else {
1733         ciInstanceKlass *k = tinst->instance_klass();
1734         field = k->get_field_by_offset(tinst->offset(), false);
1735       }
1736       assert(field == nullptr ||
1737              original_field == nullptr ||
1738              (field->holder() == original_field->holder() &&
1739               field->offset_in_bytes() == original_field->offset_in_bytes() &&
1740               field->is_static() == original_field->is_static()), "wrong field?");
1741       // Set field() and is_rewritable() attributes.
1742       if (field != nullptr)  alias_type(idx)->set_field(field);
1743     }
1744   }
1745 
1746   // Fill the cache for next time.
1747   ace->_adr_type = adr_type;
1748   ace->_index    = idx;
1749   assert(alias_type(adr_type) == alias_type(idx),  "type must be installed");
1750 
1751   // Might as well try to fill the cache for the flattened version, too.
1752   AliasCacheEntry* face = probe_alias_cache(flat);
1753   if (face->_adr_type == nullptr) {
1754     face->_adr_type = flat;
1755     face->_index    = idx;
1756     assert(alias_type(flat) == alias_type(idx), "flat type must work too");
1757   }
1758 
1759   return alias_type(idx);
1760 }
1761 
1762 
1763 Compile::AliasType* Compile::alias_type(ciField* field) {
1764   const TypeOopPtr* t;
1765   if (field->is_static())
1766     t = TypeInstPtr::make(field->holder()->java_mirror());
1767   else
1768     t = TypeOopPtr::make_from_klass_raw(field->holder());
1769   AliasType* atp = alias_type(t->add_offset(field->offset_in_bytes()), field);
1770   assert((field->is_final() || field->is_stable()) == !atp->is_rewritable(), "must get the rewritable bits correct");
1771   return atp;
1772 }
1773 
1774 
1775 //------------------------------have_alias_type--------------------------------
1776 bool Compile::have_alias_type(const TypePtr* adr_type) {
1777   AliasCacheEntry* ace = probe_alias_cache(adr_type);
1778   if (ace->_adr_type == adr_type) {
1779     return true;
1780   }
1781 
1782   // Handle special cases.
1783   if (adr_type == nullptr)             return true;
1784   if (adr_type == TypePtr::BOTTOM)  return true;
1785 
1786   return find_alias_type(adr_type, true, nullptr) != nullptr;
1787 }
1788 
1789 //-----------------------------must_alias--------------------------------------
1790 // True if all values of the given address type are in the given alias category.
1791 bool Compile::must_alias(const TypePtr* adr_type, int alias_idx) {
1792   if (alias_idx == AliasIdxBot)         return true;  // the universal category
1793   if (adr_type == nullptr)              return true;  // null serves as TypePtr::TOP
1794   if (alias_idx == AliasIdxTop)         return false; // the empty category
1795   if (adr_type->base() == Type::AnyPtr) return false; // TypePtr::BOTTOM or its twins
1796 
1797   // the only remaining possible overlap is identity
1798   int adr_idx = get_alias_index(adr_type);
1799   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1800   assert(adr_idx == alias_idx ||
1801          (alias_type(alias_idx)->adr_type() != TypeOopPtr::BOTTOM
1802           && adr_type                       != TypeOopPtr::BOTTOM),
1803          "should not be testing for overlap with an unsafe pointer");
1804   return adr_idx == alias_idx;
1805 }
1806 
1807 //------------------------------can_alias--------------------------------------
1808 // True if any values of the given address type are in the given alias category.
1809 bool Compile::can_alias(const TypePtr* adr_type, int alias_idx) {
1810   if (alias_idx == AliasIdxTop)         return false; // the empty category
1811   if (adr_type == nullptr)              return false; // null serves as TypePtr::TOP
1812   // Known instance doesn't alias with bottom memory
1813   if (alias_idx == AliasIdxBot)         return !adr_type->is_known_instance();                   // the universal category
1814   if (adr_type->base() == Type::AnyPtr) return !C->get_adr_type(alias_idx)->is_known_instance(); // TypePtr::BOTTOM or its twins
1815 
1816   // the only remaining possible overlap is identity
1817   int adr_idx = get_alias_index(adr_type);
1818   assert(adr_idx != AliasIdxBot && adr_idx != AliasIdxTop, "");
1819   return adr_idx == alias_idx;
1820 }
1821 
1822 // Mark all ParsePredicateNodes as useless. They will later be removed from the graph in IGVN together with their
1823 // uncommon traps if no Runtime Predicates were created from the Parse Predicates.
1824 void Compile::mark_parse_predicate_nodes_useless(PhaseIterGVN& igvn) {
1825   if (parse_predicate_count() == 0) {
1826     return;
1827   }
1828   for (int i = 0; i < parse_predicate_count(); i++) {
1829     ParsePredicateNode* parse_predicate = _parse_predicates.at(i);
1830     parse_predicate->mark_useless(igvn);
1831   }
1832   _parse_predicates.clear();
1833 }
1834 
1835 void Compile::record_for_post_loop_opts_igvn(Node* n) {
1836   if (!n->for_post_loop_opts_igvn()) {
1837     assert(!_for_post_loop_igvn.contains(n), "duplicate");
1838     n->add_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1839     _for_post_loop_igvn.append(n);
1840   }
1841 }
1842 
1843 void Compile::remove_from_post_loop_opts_igvn(Node* n) {
1844   n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1845   _for_post_loop_igvn.remove(n);
1846 }
1847 
1848 void Compile::process_for_post_loop_opts_igvn(PhaseIterGVN& igvn) {
1849   // Verify that all previous optimizations produced a valid graph
1850   // at least to this point, even if no loop optimizations were done.
1851   PhaseIdealLoop::verify(igvn);
1852 
1853   if (_print_phase_loop_opts) {
1854     print_method(PHASE_AFTER_LOOP_OPTS, 2);
1855   }
1856   C->set_post_loop_opts_phase(); // no more loop opts allowed
1857 
1858   assert(!C->major_progress(), "not cleared");
1859 
1860   if (_for_post_loop_igvn.length() > 0) {
1861     while (_for_post_loop_igvn.length() > 0) {
1862       Node* n = _for_post_loop_igvn.pop();
1863       n->remove_flag(Node::NodeFlags::Flag_for_post_loop_opts_igvn);
1864       igvn._worklist.push(n);
1865     }
1866     igvn.optimize();
1867     if (failing()) return;
1868     assert(_for_post_loop_igvn.length() == 0, "no more delayed nodes allowed");
1869     assert(C->parse_predicate_count() == 0, "all parse predicates should have been removed now");
1870 
1871     // Sometimes IGVN sets major progress (e.g., when processing loop nodes).
1872     if (C->major_progress()) {
1873       C->clear_major_progress(); // ensure that major progress is now clear
1874     }
1875   }
1876 }
1877 
1878 void Compile::record_for_merge_stores_igvn(Node* n) {
1879   if (!n->for_merge_stores_igvn()) {
1880     assert(!_for_merge_stores_igvn.contains(n), "duplicate");
1881     n->add_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1882     _for_merge_stores_igvn.append(n);
1883   }
1884 }
1885 
1886 void Compile::remove_from_merge_stores_igvn(Node* n) {
1887   n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1888   _for_merge_stores_igvn.remove(n);
1889 }
1890 
1891 // We need to wait with merging stores until RangeCheck smearing has removed the RangeChecks during
1892 // the post loops IGVN phase. If we do it earlier, then there may still be some RangeChecks between
1893 // the stores, and we merge the wrong sequence of stores.
1894 // Example:
1895 //   StoreI RangeCheck StoreI StoreI RangeCheck StoreI
1896 // Apply MergeStores:
1897 //   StoreI RangeCheck [   StoreL  ] RangeCheck StoreI
1898 // Remove more RangeChecks:
1899 //   StoreI            [   StoreL  ]            StoreI
1900 // But now it would have been better to do this instead:
1901 //   [         StoreL       ] [       StoreL         ]
1902 //
1903 // Note: we allow stores to merge in this dedicated IGVN round, and any later IGVN round,
1904 //       since we never unset _merge_stores_phase.
1905 void Compile::process_for_merge_stores_igvn(PhaseIterGVN& igvn) {
1906   C->set_merge_stores_phase();
1907 
1908   if (_for_merge_stores_igvn.length() > 0) {
1909     while (_for_merge_stores_igvn.length() > 0) {
1910       Node* n = _for_merge_stores_igvn.pop();
1911       n->remove_flag(Node::NodeFlags::Flag_for_merge_stores_igvn);
1912       igvn._worklist.push(n);
1913     }
1914     igvn.optimize();
1915     if (failing()) return;
1916     assert(_for_merge_stores_igvn.length() == 0, "no more delayed nodes allowed");
1917     print_method(PHASE_AFTER_MERGE_STORES, 3);
1918   }
1919 }
1920 
1921 void Compile::record_unstable_if_trap(UnstableIfTrap* trap) {
1922   if (OptimizeUnstableIf) {
1923     _unstable_if_traps.append(trap);
1924   }
1925 }
1926 
1927 void Compile::remove_useless_unstable_if_traps(Unique_Node_List& useful) {
1928   for (int i = _unstable_if_traps.length() - 1; i >= 0; i--) {
1929     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1930     Node* n = trap->uncommon_trap();
1931     if (!useful.member(n)) {
1932       _unstable_if_traps.delete_at(i); // replaces i-th with last element which is known to be useful (already processed)
1933     }
1934   }
1935 }
1936 
1937 // Remove the unstable if trap associated with 'unc' from candidates. It is either dead
1938 // or fold-compares case. Return true if succeed or not found.
1939 //
1940 // In rare cases, the found trap has been processed. It is too late to delete it. Return
1941 // false and ask fold-compares to yield.
1942 //
1943 // 'fold-compares' may use the uncommon_trap of the dominating IfNode to cover the fused
1944 // IfNode. This breaks the unstable_if trap invariant: control takes the unstable path
1945 // when deoptimization does happen.
1946 bool Compile::remove_unstable_if_trap(CallStaticJavaNode* unc, bool yield) {
1947   for (int i = 0; i < _unstable_if_traps.length(); ++i) {
1948     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1949     if (trap->uncommon_trap() == unc) {
1950       if (yield && trap->modified()) {
1951         return false;
1952       }
1953       _unstable_if_traps.delete_at(i);
1954       break;
1955     }
1956   }
1957   return true;
1958 }
1959 
1960 // Re-calculate unstable_if traps with the liveness of next_bci, which points to the unlikely path.
1961 // It needs to be done after igvn because fold-compares may fuse uncommon_traps and before renumbering.
1962 void Compile::process_for_unstable_if_traps(PhaseIterGVN& igvn) {
1963   for (int i = _unstable_if_traps.length() - 1; i >= 0; --i) {
1964     UnstableIfTrap* trap = _unstable_if_traps.at(i);
1965     CallStaticJavaNode* unc = trap->uncommon_trap();
1966     int next_bci = trap->next_bci();
1967     bool modified = trap->modified();
1968 
1969     if (next_bci != -1 && !modified) {
1970       assert(!_dead_node_list.test(unc->_idx), "changing a dead node!");
1971       JVMState* jvms = unc->jvms();
1972       ciMethod* method = jvms->method();
1973       ciBytecodeStream iter(method);
1974 
1975       iter.force_bci(jvms->bci());
1976       assert(next_bci == iter.next_bci() || next_bci == iter.get_dest(), "wrong next_bci at unstable_if");
1977       Bytecodes::Code c = iter.cur_bc();
1978       Node* lhs = nullptr;
1979       Node* rhs = nullptr;
1980       if (c == Bytecodes::_if_acmpeq || c == Bytecodes::_if_acmpne) {
1981         lhs = unc->peek_operand(0);
1982         rhs = unc->peek_operand(1);
1983       } else if (c == Bytecodes::_ifnull || c == Bytecodes::_ifnonnull) {
1984         lhs = unc->peek_operand(0);
1985       }
1986 
1987       ResourceMark rm;
1988       const MethodLivenessResult& live_locals = method->liveness_at_bci(next_bci);
1989       assert(live_locals.is_valid(), "broken liveness info");
1990       int len = (int)live_locals.size();
1991 
1992       for (int i = 0; i < len; i++) {
1993         Node* local = unc->local(jvms, i);
1994         // kill local using the liveness of next_bci.
1995         // give up when the local looks like an operand to secure reexecution.
1996         if (!live_locals.at(i) && !local->is_top() && local != lhs && local!= rhs) {
1997           uint idx = jvms->locoff() + i;
1998 #ifdef ASSERT
1999           if (PrintOpto && Verbose) {
2000             tty->print("[unstable_if] kill local#%d: ", idx);
2001             local->dump();
2002             tty->cr();
2003           }
2004 #endif
2005           igvn.replace_input_of(unc, idx, top());
2006           modified = true;
2007         }
2008       }
2009     }
2010 
2011     // keep the mondified trap for late query
2012     if (modified) {
2013       trap->set_modified();
2014     } else {
2015       _unstable_if_traps.delete_at(i);
2016     }
2017   }
2018   igvn.optimize();
2019 }
2020 
2021 // StringOpts and late inlining of string methods
2022 void Compile::inline_string_calls(bool parse_time) {
2023   {
2024     // remove useless nodes to make the usage analysis simpler
2025     ResourceMark rm;
2026     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2027   }
2028 
2029   {
2030     ResourceMark rm;
2031     print_method(PHASE_BEFORE_STRINGOPTS, 3);
2032     PhaseStringOpts pso(initial_gvn());
2033     print_method(PHASE_AFTER_STRINGOPTS, 3);
2034   }
2035 
2036   // now inline anything that we skipped the first time around
2037   if (!parse_time) {
2038     _late_inlines_pos = _late_inlines.length();
2039   }
2040 
2041   while (_string_late_inlines.length() > 0) {
2042     CallGenerator* cg = _string_late_inlines.pop();
2043     cg->do_late_inline();
2044     if (failing())  return;
2045   }
2046   _string_late_inlines.trunc_to(0);
2047 }
2048 
2049 // Late inlining of boxing methods
2050 void Compile::inline_boxing_calls(PhaseIterGVN& igvn) {
2051   if (_boxing_late_inlines.length() > 0) {
2052     assert(has_boxed_value(), "inconsistent");
2053 
2054     set_inlining_incrementally(true);
2055 
2056     igvn_worklist()->ensure_empty(); // should be done with igvn
2057 
2058     _late_inlines_pos = _late_inlines.length();
2059 
2060     while (_boxing_late_inlines.length() > 0) {
2061       CallGenerator* cg = _boxing_late_inlines.pop();
2062       cg->do_late_inline();
2063       if (failing())  return;
2064     }
2065     _boxing_late_inlines.trunc_to(0);
2066 
2067     inline_incrementally_cleanup(igvn);
2068 
2069     set_inlining_incrementally(false);
2070   }
2071 }
2072 
2073 bool Compile::inline_incrementally_one() {
2074   assert(IncrementalInline, "incremental inlining should be on");
2075   assert(_late_inlines.length() > 0, "should have been checked by caller");
2076 
2077   TracePhase tp(_t_incrInline_inline);
2078 
2079   set_inlining_progress(false);
2080   set_do_cleanup(false);
2081 
2082   for (int i = 0; i < _late_inlines.length(); i++) {
2083     _late_inlines_pos = i+1;
2084     CallGenerator* cg = _late_inlines.at(i);
2085     bool is_scheduled_for_igvn_before = C->igvn_worklist()->member(cg->call_node());
2086     bool does_dispatch = cg->is_virtual_late_inline() || cg->is_mh_late_inline();
2087     if (inlining_incrementally() || does_dispatch) { // a call can be either inlined or strength-reduced to a direct call
2088       if (should_stress_inlining()) {
2089         // randomly add repeated inline attempt if stress-inlining
2090         cg->call_node()->set_generator(cg);
2091         C->igvn_worklist()->push(cg->call_node());
2092         continue;
2093       }
2094       cg->do_late_inline();
2095       assert(_late_inlines.at(i) == cg, "no insertions before current position allowed");
2096       if (failing()) {
2097         return false;
2098       } else if (inlining_progress()) {
2099         _late_inlines_pos = i+1; // restore the position in case new elements were inserted
2100         print_method(PHASE_INCREMENTAL_INLINE_STEP, 3, cg->call_node());
2101         break; // process one call site at a time
2102       } else {
2103         bool is_scheduled_for_igvn_after = C->igvn_worklist()->member(cg->call_node());
2104         if (!is_scheduled_for_igvn_before && is_scheduled_for_igvn_after) {
2105           // Avoid potential infinite loop if node already in the IGVN list
2106           assert(false, "scheduled for IGVN during inlining attempt");
2107         } else {
2108           // Ensure call node has not disappeared from IGVN worklist during a failed inlining attempt
2109           assert(!is_scheduled_for_igvn_before || is_scheduled_for_igvn_after, "call node removed from IGVN list during inlining pass");
2110           cg->call_node()->set_generator(cg);
2111         }
2112       }
2113     } else {
2114       // Ignore late inline direct calls when inlining is not allowed.
2115       // They are left in the late inline list when node budget is exhausted until the list is fully drained.
2116     }
2117   }
2118   // Remove processed elements.
2119   _late_inlines.remove_till(_late_inlines_pos);
2120   _late_inlines_pos = 0;
2121 
2122   assert(inlining_progress() || _late_inlines.length() == 0, "no progress");
2123 
2124   bool needs_cleanup = do_cleanup() || over_inlining_cutoff();
2125 
2126   set_inlining_progress(false);
2127   set_do_cleanup(false);
2128 
2129   bool force_cleanup = directive()->IncrementalInlineForceCleanupOption;
2130   return (_late_inlines.length() > 0) && !needs_cleanup && !force_cleanup;
2131 }
2132 
2133 void Compile::inline_incrementally_cleanup(PhaseIterGVN& igvn) {
2134   {
2135     TracePhase tp(_t_incrInline_pru);
2136     ResourceMark rm;
2137     PhaseRemoveUseless pru(initial_gvn(), *igvn_worklist());
2138   }
2139   {
2140     TracePhase tp(_t_incrInline_igvn);
2141     igvn.reset();
2142     igvn.optimize();
2143     if (failing()) return;
2144   }
2145   print_method(PHASE_INCREMENTAL_INLINE_CLEANUP, 3);
2146 }
2147 
2148 template<typename E>
2149 static void shuffle_array(Compile& C, GrowableArray<E>& array) {
2150   if (array.length() < 2) {
2151     return;
2152   }
2153   for (uint i = array.length() - 1; i >= 1; i--) {
2154     uint j = C.random() % (i + 1);
2155     swap(array.at(i), array.at(j));
2156   }
2157 }
2158 
2159 void Compile::shuffle_late_inlines() {
2160   shuffle_array(*C, _late_inlines);
2161 }
2162 
2163 // Perform incremental inlining until bound on number of live nodes is reached
2164 void Compile::inline_incrementally(PhaseIterGVN& igvn) {
2165   TracePhase tp(_t_incrInline);
2166 
2167   set_inlining_incrementally(true);
2168   uint low_live_nodes = 0;
2169 
2170   if (StressIncrementalInlining) {
2171     shuffle_late_inlines();
2172   }
2173 
2174   while (_late_inlines.length() > 0) {
2175     if (live_nodes() > node_count_inlining_cutoff()) {
2176       if (low_live_nodes < node_count_inlining_cutoff() * 8 / 10) {
2177         TracePhase tp(_t_incrInline_ideal);
2178         // PhaseIdealLoop is expensive so we only try it once we are
2179         // out of live nodes and we only try it again if the previous
2180         // helped got the number of nodes down significantly
2181         PhaseIdealLoop::optimize(igvn, LoopOptsNone);
2182         if (failing())  return;
2183         low_live_nodes = live_nodes();
2184         _major_progress = true;
2185       }
2186 
2187       if (live_nodes() > node_count_inlining_cutoff()) {
2188         bool do_print_inlining = print_inlining() || print_intrinsics();
2189         if (do_print_inlining || log() != nullptr) {
2190           // Print inlining message for candidates that we couldn't inline for lack of space.
2191           for (int i = 0; i < _late_inlines.length(); i++) {
2192             CallGenerator* cg = _late_inlines.at(i);
2193             const char* msg = "live nodes > LiveNodeCountInliningCutoff";
2194             if (do_print_inlining) {
2195               inline_printer()->record(cg->method(), cg->call_node()->jvms(), InliningResult::FAILURE, msg);
2196             }
2197             log_late_inline_failure(cg, msg);
2198           }
2199         }
2200         break; // finish
2201       }
2202     }
2203 
2204     igvn_worklist()->ensure_empty(); // should be done with igvn
2205 
2206     if (_late_inlines.length() == 0) {
2207       break; // no more progress
2208     }
2209 
2210     while (inline_incrementally_one()) {
2211       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2212     }
2213     if (failing())  return;
2214 
2215     inline_incrementally_cleanup(igvn);
2216 
2217     print_method(PHASE_INCREMENTAL_INLINE_STEP, 3);
2218 
2219     if (failing())  return;
2220   }
2221 
2222   igvn_worklist()->ensure_empty(); // should be done with igvn
2223 
2224   if (_string_late_inlines.length() > 0) {
2225     assert(has_stringbuilder(), "inconsistent");
2226 
2227     inline_string_calls(false);
2228 
2229     if (failing())  return;
2230 
2231     inline_incrementally_cleanup(igvn);
2232   }
2233 
2234   set_inlining_incrementally(false);
2235 }
2236 
2237 void Compile::process_late_inline_calls_no_inline(PhaseIterGVN& igvn) {
2238   // "inlining_incrementally() == false" is used to signal that no inlining is allowed
2239   // (see LateInlineVirtualCallGenerator::do_late_inline_check() for details).
2240   // Tracking and verification of modified nodes is disabled by setting "_modified_nodes == nullptr"
2241   // as if "inlining_incrementally() == true" were set.
2242   assert(inlining_incrementally() == false, "not allowed");
2243   assert(_modified_nodes == nullptr, "not allowed");
2244   assert(_late_inlines.length() > 0, "sanity");
2245 
2246   if (StressIncrementalInlining) {
2247     shuffle_late_inlines();
2248   }
2249 
2250   while (_late_inlines.length() > 0) {
2251     igvn_worklist()->ensure_empty(); // should be done with igvn
2252 
2253     while (inline_incrementally_one()) {
2254       assert(!failing_internal() || failure_is_artificial(), "inconsistent");
2255     }
2256     if (failing())  return;
2257 
2258     inline_incrementally_cleanup(igvn);
2259   }
2260 }
2261 
2262 bool Compile::optimize_loops(PhaseIterGVN& igvn, LoopOptsMode mode) {
2263   if (_loop_opts_cnt > 0) {
2264     while (major_progress() && (_loop_opts_cnt > 0)) {
2265       TracePhase tp(_t_idealLoop);
2266       PhaseIdealLoop::optimize(igvn, mode);
2267       _loop_opts_cnt--;
2268       if (failing())  return false;
2269       if (major_progress()) {
2270         print_method(PHASE_PHASEIDEALLOOP_ITERATIONS, 2);
2271       }
2272     }
2273   }
2274   return true;
2275 }
2276 
2277 // Remove edges from "root" to each SafePoint at a backward branch.
2278 // They were inserted during parsing (see add_safepoint()) to make
2279 // infinite loops without calls or exceptions visible to root, i.e.,
2280 // useful.
2281 void Compile::remove_root_to_sfpts_edges(PhaseIterGVN& igvn) {
2282   Node *r = root();
2283   if (r != nullptr) {
2284     for (uint i = r->req(); i < r->len(); ++i) {
2285       Node *n = r->in(i);
2286       if (n != nullptr && n->is_SafePoint()) {
2287         r->rm_prec(i);
2288         if (n->outcnt() == 0) {
2289           igvn.remove_dead_node(n, PhaseIterGVN::NodeOrigin::Graph);
2290         }
2291         --i;
2292       }
2293     }
2294     // Parsing may have added top inputs to the root node (Path
2295     // leading to the Halt node proven dead). Make sure we get a
2296     // chance to clean them up.
2297     igvn._worklist.push(r);
2298     igvn.optimize();
2299   }
2300 }
2301 
2302 //------------------------------Optimize---------------------------------------
2303 // Given a graph, optimize it.
2304 void Compile::Optimize() {
2305   TracePhase tp(_t_optimizer);
2306 
2307 #ifndef PRODUCT
2308   if (env()->break_at_compile()) {
2309     BREAKPOINT;
2310   }
2311 
2312 #endif
2313 
2314   BarrierSetC2* bs = BarrierSet::barrier_set()->barrier_set_c2();
2315 #ifdef ASSERT
2316   bs->verify_gc_barriers(this, BarrierSetC2::BeforeOptimize);
2317 #endif
2318 
2319   ResourceMark rm;
2320 
2321   NOT_PRODUCT( verify_graph_edges(); )
2322 
2323   print_method(PHASE_AFTER_PARSING, 1);
2324 
2325  {
2326   // Iterative Global Value Numbering, including ideal transforms
2327   PhaseIterGVN igvn;
2328 #ifdef ASSERT
2329   _modified_nodes = new (comp_arena()) Unique_Node_List(comp_arena());
2330 #endif
2331   {
2332     TracePhase tp(_t_iterGVN);
2333     igvn.optimize(true);
2334   }
2335 
2336   if (failing())  return;
2337 
2338   print_method(PHASE_ITER_GVN1, 2);
2339 
2340   process_for_unstable_if_traps(igvn);
2341 
2342   if (failing())  return;
2343 
2344   inline_incrementally(igvn);
2345 
2346   print_method(PHASE_INCREMENTAL_INLINE, 2);
2347 
2348   if (failing())  return;
2349 
2350   if (eliminate_boxing()) {
2351     // Inline valueOf() methods now.
2352     inline_boxing_calls(igvn);
2353 
2354     if (failing())  return;
2355 
2356     if (AlwaysIncrementalInline || StressIncrementalInlining) {
2357       inline_incrementally(igvn);
2358     }
2359 
2360     print_method(PHASE_INCREMENTAL_BOXING_INLINE, 2);
2361 
2362     if (failing())  return;
2363   }
2364 
2365   // Remove the speculative part of types and clean up the graph from
2366   // the extra CastPP nodes whose only purpose is to carry them. Do
2367   // that early so that optimizations are not disrupted by the extra
2368   // CastPP nodes.
2369   remove_speculative_types(igvn);
2370 
2371   if (failing())  return;
2372 
2373   // No more new expensive nodes will be added to the list from here
2374   // so keep only the actual candidates for optimizations.
2375   cleanup_expensive_nodes(igvn);
2376 
2377   if (failing())  return;
2378 
2379   assert(EnableVectorSupport || !has_vbox_nodes(), "sanity");
2380   if (EnableVectorSupport && has_vbox_nodes()) {
2381     TracePhase tp(_t_vector);
2382     PhaseVector pv(igvn);
2383     pv.optimize_vector_boxes();
2384     if (failing())  return;
2385     print_method(PHASE_ITER_GVN_AFTER_VECTOR, 2);
2386   }
2387   assert(!has_vbox_nodes(), "sanity");
2388 
2389   if (!failing() && RenumberLiveNodes && live_nodes() + NodeLimitFudgeFactor < unique()) {
2390     Compile::TracePhase tp(_t_renumberLive);
2391     igvn_worklist()->ensure_empty(); // should be done with igvn
2392     {
2393       ResourceMark rm;
2394       PhaseRenumberLive prl(initial_gvn(), *igvn_worklist());
2395     }
2396     igvn.reset();
2397     igvn.optimize(true);
2398     if (failing()) return;
2399   }
2400 
2401   // Now that all inlining is over and no PhaseRemoveUseless will run, cut edge from root to loop
2402   // safepoints
2403   remove_root_to_sfpts_edges(igvn);
2404 
2405   if (failing())  return;
2406 
2407   _print_phase_loop_opts = has_loops();
2408   if (_print_phase_loop_opts) {
2409     print_method(PHASE_BEFORE_LOOP_OPTS, 2);
2410   }
2411 
2412   // Perform escape analysis
2413   if (do_escape_analysis() && ConnectionGraph::has_candidates(this)) {
2414     if (has_loops()) {
2415       // Cleanup graph (remove dead nodes).
2416       TracePhase tp(_t_idealLoop);
2417       PhaseIdealLoop::optimize(igvn, LoopOptsMaxUnroll);
2418       if (failing())  return;
2419     }
2420     bool progress;
2421     print_method(PHASE_PHASEIDEAL_BEFORE_EA, 2);
2422     do {
2423       ConnectionGraph::do_analysis(this, &igvn);
2424 
2425       if (failing())  return;
2426 
2427       int mcount = macro_count(); // Record number of allocations and locks before IGVN
2428 
2429       // Optimize out fields loads from scalar replaceable allocations.
2430       igvn.optimize(true);
2431       print_method(PHASE_ITER_GVN_AFTER_EA, 2);
2432 
2433       if (failing()) return;
2434 
2435       if (congraph() != nullptr && macro_count() > 0) {
2436         TracePhase tp(_t_macroEliminate);
2437         PhaseMacroExpand mexp(igvn);
2438         mexp.eliminate_macro_nodes();
2439         if (failing()) return;
2440         print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2441 
2442         igvn.set_delay_transform(false);
2443         igvn.optimize();
2444         if (failing()) return;
2445 
2446         print_method(PHASE_ITER_GVN_AFTER_ELIMINATION, 2);
2447       }
2448 
2449       ConnectionGraph::verify_ram_nodes(this, root());
2450       if (failing())  return;
2451 
2452       progress = do_iterative_escape_analysis() &&
2453                  (macro_count() < mcount) &&
2454                  ConnectionGraph::has_candidates(this);
2455       // Try again if candidates exist and made progress
2456       // by removing some allocations and/or locks.
2457     } while (progress);
2458   }
2459 
2460   // Loop transforms on the ideal graph.  Range Check Elimination,
2461   // peeling, unrolling, etc.
2462 
2463   // Set loop opts counter
2464   if((_loop_opts_cnt > 0) && (has_loops() || has_split_ifs())) {
2465     {
2466       TracePhase tp(_t_idealLoop);
2467       PhaseIdealLoop::optimize(igvn, LoopOptsDefault);
2468       _loop_opts_cnt--;
2469       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP1, 2);
2470       if (failing())  return;
2471     }
2472     // Loop opts pass if partial peeling occurred in previous pass
2473     if(PartialPeelLoop && major_progress() && (_loop_opts_cnt > 0)) {
2474       TracePhase tp(_t_idealLoop);
2475       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2476       _loop_opts_cnt--;
2477       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP2, 2);
2478       if (failing())  return;
2479     }
2480     // Loop opts pass for loop-unrolling before CCP
2481     if(major_progress() && (_loop_opts_cnt > 0)) {
2482       TracePhase tp(_t_idealLoop);
2483       PhaseIdealLoop::optimize(igvn, LoopOptsSkipSplitIf);
2484       _loop_opts_cnt--;
2485       if (major_progress()) print_method(PHASE_PHASEIDEALLOOP3, 2);
2486     }
2487     if (!failing()) {
2488       // Verify that last round of loop opts produced a valid graph
2489       PhaseIdealLoop::verify(igvn);
2490     }
2491   }
2492   if (failing())  return;
2493 
2494   // Conditional Constant Propagation;
2495   print_method(PHASE_BEFORE_CCP1, 2);
2496   PhaseCCP ccp( &igvn );
2497   assert( true, "Break here to ccp.dump_nodes_and_types(_root,999,1)");
2498   {
2499     TracePhase tp(_t_ccp);
2500     ccp.do_transform();
2501   }
2502   print_method(PHASE_CCP1, 2);
2503 
2504   assert( true, "Break here to ccp.dump_old2new_map()");
2505 
2506   // Iterative Global Value Numbering, including ideal transforms
2507   {
2508     TracePhase tp(_t_iterGVN2);
2509     igvn.reset_from_igvn(&ccp);
2510     igvn.optimize(true);
2511   }
2512   print_method(PHASE_ITER_GVN2, 2);
2513 
2514   if (failing())  return;
2515 
2516   // Loop transforms on the ideal graph.  Range Check Elimination,
2517   // peeling, unrolling, etc.
2518   if (!optimize_loops(igvn, LoopOptsDefault)) {
2519     return;
2520   }
2521 
2522   C->clear_major_progress(); // ensure that major progress is now clear
2523 
2524   process_for_post_loop_opts_igvn(igvn);
2525 
2526   if (failing())  return;
2527 
2528   // Once loop optimizations are over, it is safe to get rid of all reachability fence nodes and
2529   // migrate reachability edges to safepoints.
2530   if (OptimizeReachabilityFences && _reachability_fences.length() > 0) {
2531     TracePhase tp1(_t_idealLoop);
2532     TracePhase tp2(_t_reachability);
2533     PhaseIdealLoop::optimize(igvn, PostLoopOptsExpandReachabilityFences);
2534     print_method(PHASE_EXPAND_REACHABILITY_FENCES, 2);
2535     if (failing())  return;
2536     assert(_reachability_fences.length() == 0 || PreserveReachabilityFencesOnConstants, "no RF nodes allowed");
2537   }
2538 
2539   process_for_merge_stores_igvn(igvn);
2540 
2541   if (failing())  return;
2542 
2543 #ifdef ASSERT
2544   bs->verify_gc_barriers(this, BarrierSetC2::BeforeMacroExpand);
2545 #endif
2546 
2547   {
2548     TracePhase tp(_t_macroExpand);
2549     print_method(PHASE_BEFORE_MACRO_EXPANSION, 3);
2550     PhaseMacroExpand  mex(igvn);
2551     // Do not allow new macro nodes once we start to eliminate and expand
2552     C->reset_allow_macro_nodes();
2553     // Last attempt to eliminate macro nodes before expand
2554     mex.eliminate_macro_nodes();
2555     if (failing()) {
2556       return;
2557     }
2558     mex.eliminate_opaque_looplimit_macro_nodes();
2559     if (failing()) {
2560       return;
2561     }
2562     print_method(PHASE_AFTER_MACRO_ELIMINATION, 2);
2563     if (mex.expand_macro_nodes()) {
2564       assert(failing(), "must bail out w/ explicit message");
2565       return;
2566     }
2567     print_method(PHASE_AFTER_MACRO_EXPANSION, 2);
2568   }
2569 
2570   {
2571     TracePhase tp(_t_barrierExpand);
2572     if (bs->expand_barriers(this, igvn)) {
2573       assert(failing(), "must bail out w/ explicit message");
2574       return;
2575     }
2576     print_method(PHASE_BARRIER_EXPANSION, 2);
2577   }
2578 
2579   if (C->max_vector_size() > 0) {
2580     C->optimize_logic_cones(igvn);
2581     igvn.optimize();
2582     if (failing()) return;
2583   }
2584 
2585   DEBUG_ONLY( _modified_nodes = nullptr; )
2586 
2587   assert(igvn._worklist.size() == 0, "not empty");
2588 
2589   if (_late_inlines.length() > 0) {
2590     // More opportunities to optimize virtual and MH calls.
2591     // Though it's maybe too late to perform inlining, strength-reducing them to direct calls is still an option.
2592     process_late_inline_calls_no_inline(igvn);
2593     if (failing())  return;
2594   }
2595   assert(_late_inlines.length() == 0, "late inline queue must be drained");
2596  } // (End scope of igvn; run destructor if necessary for asserts.)
2597 
2598  check_no_dead_use();
2599 
2600  // We will never use the NodeHash table any more. Clear it so that final_graph_reshaping does not have
2601  // to remove hashes to unlock nodes for modifications.
2602  C->node_hash()->clear();
2603 
2604  // A method with only infinite loops has no edges entering loops from root
2605  {
2606    TracePhase tp(_t_graphReshaping);
2607    if (final_graph_reshaping()) {
2608      assert(failing(), "must bail out w/ explicit message");
2609      return;
2610    }
2611  }
2612 
2613  print_method(PHASE_OPTIMIZE_FINISHED, 2);
2614  DEBUG_ONLY(set_phase_optimize_finished();)
2615 }
2616 
2617 #ifdef ASSERT
2618 void Compile::check_no_dead_use() const {
2619   ResourceMark rm;
2620   Unique_Node_List wq;
2621   wq.push(root());
2622   for (uint i = 0; i < wq.size(); ++i) {
2623     Node* n = wq.at(i);
2624     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++) {
2625       Node* u = n->fast_out(j);
2626       if (u->outcnt() == 0 && !u->is_Con()) {
2627         u->dump();
2628         fatal("no reachable node should have no use");
2629       }
2630       wq.push(u);
2631     }
2632   }
2633 }
2634 #endif
2635 
2636 void Compile::inline_vector_reboxing_calls() {
2637   if (C->_vector_reboxing_late_inlines.length() > 0) {
2638     _late_inlines_pos = C->_late_inlines.length();
2639     while (_vector_reboxing_late_inlines.length() > 0) {
2640       CallGenerator* cg = _vector_reboxing_late_inlines.pop();
2641       cg->do_late_inline();
2642       if (failing())  return;
2643       print_method(PHASE_INLINE_VECTOR_REBOX, 3, cg->call_node());
2644     }
2645     _vector_reboxing_late_inlines.trunc_to(0);
2646   }
2647 }
2648 
2649 bool Compile::has_vbox_nodes() {
2650   if (C->_vector_reboxing_late_inlines.length() > 0) {
2651     return true;
2652   }
2653   for (int macro_idx = C->macro_count() - 1; macro_idx >= 0; macro_idx--) {
2654     Node * n = C->macro_node(macro_idx);
2655     assert(n->is_macro(), "only macro nodes expected here");
2656     if (n->Opcode() == Op_VectorUnbox || n->Opcode() == Op_VectorBox || n->Opcode() == Op_VectorBoxAllocate) {
2657       return true;
2658     }
2659   }
2660   return false;
2661 }
2662 
2663 //---------------------------- Bitwise operation packing optimization ---------------------------
2664 
2665 static bool is_vector_unary_bitwise_op(Node* n) {
2666   return n->Opcode() == Op_XorV &&
2667          VectorNode::is_vector_bitwise_not_pattern(n);
2668 }
2669 
2670 static bool is_vector_binary_bitwise_op(Node* n) {
2671   switch (n->Opcode()) {
2672     case Op_AndV:
2673     case Op_OrV:
2674       return true;
2675 
2676     case Op_XorV:
2677       return !is_vector_unary_bitwise_op(n);
2678 
2679     default:
2680       return false;
2681   }
2682 }
2683 
2684 static bool is_vector_ternary_bitwise_op(Node* n) {
2685   return n->Opcode() == Op_MacroLogicV;
2686 }
2687 
2688 static bool is_vector_bitwise_op(Node* n) {
2689   return is_vector_unary_bitwise_op(n)  ||
2690          is_vector_binary_bitwise_op(n) ||
2691          is_vector_ternary_bitwise_op(n);
2692 }
2693 
2694 static bool is_vector_bitwise_cone_root(Node* n) {
2695   if (n->bottom_type()->isa_pvectmask() || !is_vector_bitwise_op(n)) {
2696     return false;
2697   }
2698   for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
2699     if (is_vector_bitwise_op(n->fast_out(i))) {
2700       return false;
2701     }
2702   }
2703   return true;
2704 }
2705 
2706 static uint collect_unique_inputs(Node* n, Unique_Node_List& inputs) {
2707   uint cnt = 0;
2708   if (is_vector_bitwise_op(n)) {
2709     uint inp_cnt = n->is_predicated_vector() ? n->req()-1 : n->req();
2710     if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2711       for (uint i = 1; i < inp_cnt; i++) {
2712         Node* in = n->in(i);
2713         bool skip = VectorNode::is_all_ones_vector(in);
2714         if (!skip && !inputs.member(in)) {
2715           inputs.push(in);
2716           cnt++;
2717         }
2718       }
2719       assert(cnt <= 1, "not unary");
2720     } else {
2721       uint last_req = inp_cnt;
2722       if (is_vector_ternary_bitwise_op(n)) {
2723         last_req = inp_cnt - 1; // skip last input
2724       }
2725       for (uint i = 1; i < last_req; i++) {
2726         Node* def = n->in(i);
2727         if (!inputs.member(def)) {
2728           inputs.push(def);
2729           cnt++;
2730         }
2731       }
2732     }
2733   } else { // not a bitwise operations
2734     if (!inputs.member(n)) {
2735       inputs.push(n);
2736       cnt++;
2737     }
2738   }
2739   return cnt;
2740 }
2741 
2742 void Compile::collect_logic_cone_roots(Unique_Node_List& list) {
2743   Unique_Node_List useful_nodes;
2744   C->identify_useful_nodes(useful_nodes);
2745 
2746   for (uint i = 0; i < useful_nodes.size(); i++) {
2747     Node* n = useful_nodes.at(i);
2748     if (is_vector_bitwise_cone_root(n)) {
2749       list.push(n);
2750     }
2751   }
2752 }
2753 
2754 Node* Compile::xform_to_MacroLogicV(PhaseIterGVN& igvn,
2755                                     const TypeVect* vt,
2756                                     Unique_Node_List& partition,
2757                                     Unique_Node_List& inputs) {
2758   assert(partition.size() == 2 || partition.size() == 3, "not supported");
2759   assert(inputs.size()    == 2 || inputs.size()    == 3, "not supported");
2760   assert(Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type()), "not supported");
2761 
2762   Node* in1 = inputs.at(0);
2763   Node* in2 = inputs.at(1);
2764   Node* in3 = (inputs.size() == 3 ? inputs.at(2) : in2);
2765 
2766   uint func = compute_truth_table(partition, inputs);
2767 
2768   Node* pn = partition.at(partition.size() - 1);
2769   Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
2770   return igvn.transform(MacroLogicVNode::make(igvn, in1, in2, in3, mask, func, vt));
2771 }
2772 
2773 static uint extract_bit(uint func, uint pos) {
2774   return (func & (1 << pos)) >> pos;
2775 }
2776 
2777 //
2778 //  A macro logic node represents a truth table. It has 4 inputs,
2779 //  First three inputs corresponds to 3 columns of a truth table
2780 //  and fourth input captures the logic function.
2781 //
2782 //  eg.  fn = (in1 AND in2) OR in3;
2783 //
2784 //      MacroNode(in1,in2,in3,fn)
2785 //
2786 //  -----------------
2787 //  in1 in2 in3  fn
2788 //  -----------------
2789 //  0    0   0    0
2790 //  0    0   1    1
2791 //  0    1   0    0
2792 //  0    1   1    1
2793 //  1    0   0    0
2794 //  1    0   1    1
2795 //  1    1   0    1
2796 //  1    1   1    1
2797 //
2798 
2799 uint Compile::eval_macro_logic_op(uint func, uint in1 , uint in2, uint in3) {
2800   int res = 0;
2801   for (int i = 0; i < 8; i++) {
2802     int bit1 = extract_bit(in1, i);
2803     int bit2 = extract_bit(in2, i);
2804     int bit3 = extract_bit(in3, i);
2805 
2806     int func_bit_pos = (bit1 << 2 | bit2 << 1 | bit3);
2807     int func_bit = extract_bit(func, func_bit_pos);
2808 
2809     res |= func_bit << i;
2810   }
2811   return res;
2812 }
2813 
2814 static uint eval_operand(Node* n, HashTable<Node*,uint>& eval_map) {
2815   assert(n != nullptr, "");
2816   assert(eval_map.contains(n), "absent");
2817   return *(eval_map.get(n));
2818 }
2819 
2820 static void eval_operands(Node* n,
2821                           uint& func1, uint& func2, uint& func3,
2822                           HashTable<Node*,uint>& eval_map) {
2823   assert(is_vector_bitwise_op(n), "");
2824 
2825   if (is_vector_unary_bitwise_op(n)) {
2826     Node* opnd = n->in(1);
2827     if (VectorNode::is_vector_bitwise_not_pattern(n) && VectorNode::is_all_ones_vector(opnd)) {
2828       opnd = n->in(2);
2829     }
2830     func1 = eval_operand(opnd, eval_map);
2831   } else if (is_vector_binary_bitwise_op(n)) {
2832     func1 = eval_operand(n->in(1), eval_map);
2833     func2 = eval_operand(n->in(2), eval_map);
2834   } else {
2835     assert(is_vector_ternary_bitwise_op(n), "unknown operation");
2836     func1 = eval_operand(n->in(1), eval_map);
2837     func2 = eval_operand(n->in(2), eval_map);
2838     func3 = eval_operand(n->in(3), eval_map);
2839   }
2840 }
2841 
2842 uint Compile::compute_truth_table(Unique_Node_List& partition, Unique_Node_List& inputs) {
2843   assert(inputs.size() <= 3, "sanity");
2844   ResourceMark rm;
2845   uint res = 0;
2846   HashTable<Node*,uint> eval_map;
2847 
2848   // Populate precomputed functions for inputs.
2849   // Each input corresponds to one column of 3 input truth-table.
2850   uint input_funcs[] = { 0xAA,   // (_, _, c) -> c
2851                          0xCC,   // (_, b, _) -> b
2852                          0xF0 }; // (a, _, _) -> a
2853   for (uint i = 0; i < inputs.size(); i++) {
2854     eval_map.put(inputs.at(i), input_funcs[2-i]);
2855   }
2856 
2857   for (uint i = 0; i < partition.size(); i++) {
2858     Node* n = partition.at(i);
2859 
2860     uint func1 = 0, func2 = 0, func3 = 0;
2861     eval_operands(n, func1, func2, func3, eval_map);
2862 
2863     switch (n->Opcode()) {
2864       case Op_OrV:
2865         assert(func3 == 0, "not binary");
2866         res = func1 | func2;
2867         break;
2868       case Op_AndV:
2869         assert(func3 == 0, "not binary");
2870         res = func1 & func2;
2871         break;
2872       case Op_XorV:
2873         if (VectorNode::is_vector_bitwise_not_pattern(n)) {
2874           assert(func2 == 0 && func3 == 0, "not unary");
2875           res = (~func1) & 0xFF;
2876         } else {
2877           assert(func3 == 0, "not binary");
2878           res = func1 ^ func2;
2879         }
2880         break;
2881       case Op_MacroLogicV:
2882         // Ordering of inputs may change during evaluation of sub-tree
2883         // containing MacroLogic node as a child node, thus a re-evaluation
2884         // makes sure that function is evaluated in context of current
2885         // inputs.
2886         res = eval_macro_logic_op(n->in(4)->get_int(), func1, func2, func3);
2887         break;
2888 
2889       default: assert(false, "not supported: %s", n->Name());
2890     }
2891     assert(res <= 0xFF, "invalid");
2892     eval_map.put(n, res);
2893   }
2894   return res;
2895 }
2896 
2897 // Criteria under which nodes gets packed into a macro logic node:-
2898 //  1) Parent and both child nodes are all unmasked or masked with
2899 //     same predicates.
2900 //  2) Masked parent can be packed with left child if it is predicated
2901 //     and both have same predicates.
2902 //  3) Masked parent can be packed with right child if its un-predicated
2903 //     or has matching predication condition.
2904 //  4) An unmasked parent can be packed with an unmasked child.
2905 bool Compile::compute_logic_cone(Node* n, Unique_Node_List& partition, Unique_Node_List& inputs) {
2906   assert(partition.size() == 0, "not empty");
2907   assert(inputs.size() == 0, "not empty");
2908   if (is_vector_ternary_bitwise_op(n)) {
2909     return false;
2910   }
2911 
2912   bool is_unary_op = is_vector_unary_bitwise_op(n);
2913   if (is_unary_op) {
2914     assert(collect_unique_inputs(n, inputs) == 1, "not unary");
2915     return false; // too few inputs
2916   }
2917 
2918   bool pack_left_child = true;
2919   bool pack_right_child = true;
2920 
2921   bool left_child_LOP = is_vector_bitwise_op(n->in(1));
2922   bool right_child_LOP = is_vector_bitwise_op(n->in(2));
2923 
2924   int left_child_input_cnt = 0;
2925   int right_child_input_cnt = 0;
2926 
2927   bool parent_is_predicated = n->is_predicated_vector();
2928   bool left_child_predicated = n->in(1)->is_predicated_vector();
2929   bool right_child_predicated = n->in(2)->is_predicated_vector();
2930 
2931   Node* parent_pred = parent_is_predicated ? n->in(n->req()-1) : nullptr;
2932   Node* left_child_pred = left_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2933   Node* right_child_pred = right_child_predicated ? n->in(1)->in(n->in(1)->req()-1) : nullptr;
2934 
2935   do {
2936     if (pack_left_child && left_child_LOP &&
2937         ((!parent_is_predicated && !left_child_predicated) ||
2938         ((parent_is_predicated && left_child_predicated &&
2939           parent_pred == left_child_pred)))) {
2940        partition.push(n->in(1));
2941        left_child_input_cnt = collect_unique_inputs(n->in(1), inputs);
2942     } else {
2943        inputs.push(n->in(1));
2944        left_child_input_cnt = 1;
2945     }
2946 
2947     if (pack_right_child && right_child_LOP &&
2948         (!right_child_predicated ||
2949          (right_child_predicated && parent_is_predicated &&
2950           parent_pred == right_child_pred))) {
2951        partition.push(n->in(2));
2952        right_child_input_cnt = collect_unique_inputs(n->in(2), inputs);
2953     } else {
2954        inputs.push(n->in(2));
2955        right_child_input_cnt = 1;
2956     }
2957 
2958     if (inputs.size() > 3) {
2959       assert(partition.size() > 0, "");
2960       inputs.clear();
2961       partition.clear();
2962       if (left_child_input_cnt > right_child_input_cnt) {
2963         pack_left_child = false;
2964       } else {
2965         pack_right_child = false;
2966       }
2967     } else {
2968       break;
2969     }
2970   } while(true);
2971 
2972   if(partition.size()) {
2973     partition.push(n);
2974   }
2975 
2976   return (partition.size() == 2 || partition.size() == 3) &&
2977          (inputs.size()    == 2 || inputs.size()    == 3);
2978 }
2979 
2980 void Compile::process_logic_cone_root(PhaseIterGVN &igvn, Node *n, VectorSet &visited) {
2981   assert(is_vector_bitwise_op(n), "not a root");
2982 
2983   visited.set(n->_idx);
2984 
2985   // 1) Do a DFS walk over the logic cone.
2986   for (uint i = 1; i < n->req(); i++) {
2987     Node* in = n->in(i);
2988     if (!visited.test(in->_idx) && is_vector_bitwise_op(in)) {
2989       process_logic_cone_root(igvn, in, visited);
2990     }
2991   }
2992 
2993   // 2) Bottom up traversal: Merge node[s] with
2994   // the parent to form macro logic node.
2995   Unique_Node_List partition;
2996   Unique_Node_List inputs;
2997   if (compute_logic_cone(n, partition, inputs)) {
2998     const TypeVect* vt = n->bottom_type()->is_vect();
2999     Node* pn = partition.at(partition.size() - 1);
3000     Node* mask = pn->is_predicated_vector() ? pn->in(pn->req()-1) : nullptr;
3001     if (mask == nullptr ||
3002         Matcher::match_rule_supported_vector_masked(Op_MacroLogicV, vt->length(), vt->element_basic_type())) {
3003       Node* macro_logic = xform_to_MacroLogicV(igvn, vt, partition, inputs);
3004       VectorNode::trace_new_vector(macro_logic, "MacroLogic");
3005       igvn.replace_node(n, macro_logic);
3006     }
3007   }
3008 }
3009 
3010 void Compile::optimize_logic_cones(PhaseIterGVN &igvn) {
3011   ResourceMark rm;
3012   if (Matcher::match_rule_supported(Op_MacroLogicV)) {
3013     Unique_Node_List list;
3014     collect_logic_cone_roots(list);
3015 
3016     while (list.size() > 0) {
3017       Node* n = list.pop();
3018       const TypeVect* vt = n->bottom_type()->is_vect();
3019       bool supported = Matcher::match_rule_supported_vector(Op_MacroLogicV, vt->length(), vt->element_basic_type());
3020       if (supported) {
3021         VectorSet visited(comp_arena());
3022         process_logic_cone_root(igvn, n, visited);
3023       }
3024     }
3025   }
3026 }
3027 
3028 //------------------------------Code_Gen---------------------------------------
3029 // Given a graph, generate code for it
3030 void Compile::Code_Gen() {
3031   if (failing()) {
3032     return;
3033   }
3034 
3035   // Perform instruction selection.  You might think we could reclaim Matcher
3036   // memory PDQ, but actually the Matcher is used in generating spill code.
3037   // Internals of the Matcher (including some VectorSets) must remain live
3038   // for awhile - thus I cannot reclaim Matcher memory lest a VectorSet usage
3039   // set a bit in reclaimed memory.
3040 
3041   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3042   // nodes.  Mapping is only valid at the root of each matched subtree.
3043   NOT_PRODUCT( verify_graph_edges(); )
3044 
3045   Matcher matcher;
3046   _matcher = &matcher;
3047   {
3048     TracePhase tp(_t_matcher);
3049     matcher.match();
3050     if (failing()) {
3051       return;
3052     }
3053   }
3054   // In debug mode can dump m._nodes.dump() for mapping of ideal to machine
3055   // nodes.  Mapping is only valid at the root of each matched subtree.
3056   NOT_PRODUCT( verify_graph_edges(); )
3057 
3058   // If you have too many nodes, or if matching has failed, bail out
3059   check_node_count(0, "out of nodes matching instructions");
3060   if (failing()) {
3061     return;
3062   }
3063 
3064   print_method(PHASE_MATCHING, 2);
3065 
3066   // Build a proper-looking CFG
3067   PhaseCFG cfg(node_arena(), root(), matcher);
3068   if (failing()) {
3069     return;
3070   }
3071   _cfg = &cfg;
3072   {
3073     TracePhase tp(_t_scheduler);
3074     bool success = cfg.do_global_code_motion();
3075     if (!success) {
3076       return;
3077     }
3078 
3079     print_method(PHASE_GLOBAL_CODE_MOTION, 2);
3080     NOT_PRODUCT( verify_graph_edges(); )
3081     cfg.verify();
3082     if (failing()) {
3083       return;
3084     }
3085   }
3086 
3087   PhaseChaitin regalloc(unique(), cfg, matcher, false);
3088   _regalloc = &regalloc;
3089   {
3090     TracePhase tp(_t_registerAllocation);
3091     // Perform register allocation.  After Chaitin, use-def chains are
3092     // no longer accurate (at spill code) and so must be ignored.
3093     // Node->LRG->reg mappings are still accurate.
3094     _regalloc->Register_Allocate();
3095 
3096     // Bail out if the allocator builds too many nodes
3097     if (failing()) {
3098       return;
3099     }
3100 
3101     print_method(PHASE_REGISTER_ALLOCATION, 2);
3102   }
3103 
3104   // Prior to register allocation we kept empty basic blocks in case the
3105   // the allocator needed a place to spill.  After register allocation we
3106   // are not adding any new instructions.  If any basic block is empty, we
3107   // can now safely remove it.
3108   {
3109     TracePhase tp(_t_blockOrdering);
3110     cfg.remove_empty_blocks();
3111     if (do_freq_based_layout()) {
3112       PhaseBlockLayout layout(cfg);
3113     } else {
3114       cfg.set_loop_alignment();
3115     }
3116     cfg.fixup_flow();
3117     cfg.remove_unreachable_blocks();
3118     cfg.verify_dominator_tree();
3119     print_method(PHASE_BLOCK_ORDERING, 3);
3120   }
3121 
3122   // Apply peephole optimizations
3123   if( OptoPeephole ) {
3124     TracePhase tp(_t_peephole);
3125     PhasePeephole peep( _regalloc, cfg);
3126     peep.do_transform();
3127     print_method(PHASE_PEEPHOLE, 3);
3128   }
3129 
3130   // Do late expand if CPU requires this.
3131   if (Matcher::require_postalloc_expand) {
3132     TracePhase tp(_t_postalloc_expand);
3133     cfg.postalloc_expand(_regalloc);
3134     print_method(PHASE_POSTALLOC_EXPAND, 3);
3135   }
3136 
3137 #ifdef ASSERT
3138   {
3139     CompilationMemoryStatistic::do_test_allocations();
3140     if (failing()) return;
3141   }
3142 #endif
3143 
3144   // Convert Nodes to instruction bits in a buffer
3145   {
3146     TracePhase tp(_t_output);
3147     PhaseOutput output;
3148     output.Output();
3149     if (failing())  return;
3150     output.install();
3151     print_method(PHASE_FINAL_CODE, 1); // Compile::_output is not null here
3152   }
3153 
3154   // He's dead, Jim.
3155   _cfg     = (PhaseCFG*)((intptr_t)0xdeadbeef);
3156   _regalloc = (PhaseChaitin*)((intptr_t)0xdeadbeef);
3157 }
3158 
3159 //------------------------------Final_Reshape_Counts---------------------------
3160 // This class defines counters to help identify when a method
3161 // may/must be executed using hardware with only 24-bit precision.
3162 struct Final_Reshape_Counts : public StackObj {
3163   int  _call_count;             // count non-inlined 'common' calls
3164   int  _float_count;            // count float ops requiring 24-bit precision
3165   int  _double_count;           // count double ops requiring more precision
3166   int  _java_call_count;        // count non-inlined 'java' calls
3167   int  _inner_loop_count;       // count loops which need alignment
3168   VectorSet _visited;           // Visitation flags
3169   Node_List _tests;             // Set of IfNodes & PCTableNodes
3170 
3171   Final_Reshape_Counts() :
3172     _call_count(0), _float_count(0), _double_count(0),
3173     _java_call_count(0), _inner_loop_count(0) { }
3174 
3175   void inc_call_count  () { _call_count  ++; }
3176   void inc_float_count () { _float_count ++; }
3177   void inc_double_count() { _double_count++; }
3178   void inc_java_call_count() { _java_call_count++; }
3179   void inc_inner_loop_count() { _inner_loop_count++; }
3180 
3181   int  get_call_count  () const { return _call_count  ; }
3182   int  get_float_count () const { return _float_count ; }
3183   int  get_double_count() const { return _double_count; }
3184   int  get_java_call_count() const { return _java_call_count; }
3185   int  get_inner_loop_count() const { return _inner_loop_count; }
3186 };
3187 
3188 //------------------------------final_graph_reshaping_impl----------------------
3189 // Implement items 1-5 from final_graph_reshaping below.
3190 void Compile::final_graph_reshaping_impl(Node *n, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3191 
3192   if ( n->outcnt() == 0 ) return; // dead node
3193   uint nop = n->Opcode();
3194 
3195   // Check for 2-input instruction with "last use" on right input.
3196   // Swap to left input.  Implements item (2).
3197   if( n->req() == 3 &&          // two-input instruction
3198       n->in(1)->outcnt() > 1 && // left use is NOT a last use
3199       (!n->in(1)->is_Phi() || n->in(1)->in(2) != n) && // it is not data loop
3200       n->in(2)->outcnt() == 1 &&// right use IS a last use
3201       !n->in(2)->is_Con() ) {   // right use is not a constant
3202     // Check for commutative opcode
3203     switch( nop ) {
3204     case Op_AddI:  case Op_AddF:  case Op_AddD:  case Op_AddHF:  case Op_AddL:
3205     case Op_MaxI:  case Op_MaxL:  case Op_MaxF:  case Op_MaxD:
3206     case Op_MinI:  case Op_MinL:  case Op_MinF:  case Op_MinD:
3207     case Op_MulI:  case Op_MulF:  case Op_MulD:  case Op_MulHF:  case Op_MulL:
3208     case Op_AndL:  case Op_XorL:  case Op_OrL:
3209     case Op_AndI:  case Op_XorI:  case Op_OrI: {
3210       // Move "last use" input to left by swapping inputs
3211       n->swap_edges(1, 2);
3212       break;
3213     }
3214     default:
3215       break;
3216     }
3217   }
3218 
3219 #ifdef ASSERT
3220   if( n->is_Mem() ) {
3221     int alias_idx = get_alias_index(n->as_Mem()->adr_type());
3222     assert( n->in(0) != nullptr || alias_idx != Compile::AliasIdxRaw ||
3223             // oop will be recorded in oop map if load crosses safepoint
3224             (n->is_Load() && (n->as_Load()->bottom_type()->isa_oopptr() ||
3225                               LoadNode::is_immutable_value(n->in(MemNode::Address)))),
3226             "raw memory operations should have control edge");
3227   }
3228   if (n->is_MemBar()) {
3229     MemBarNode* mb = n->as_MemBar();
3230     if (mb->trailing_store() || mb->trailing_load_store()) {
3231       assert(mb->leading_membar()->trailing_membar() == mb, "bad membar pair");
3232       Node* mem = BarrierSet::barrier_set()->barrier_set_c2()->step_over_gc_barrier(mb->in(MemBarNode::Precedent));
3233       assert((mb->trailing_store() && mem->is_Store() && mem->as_Store()->is_release()) ||
3234              (mb->trailing_load_store() && mem->is_LoadStore()), "missing mem op");
3235     } else if (mb->leading()) {
3236       assert(mb->trailing_membar()->leading_membar() == mb, "bad membar pair");
3237     }
3238   }
3239   if (n->is_CallLeafPure()) {
3240     // A pure call whose result projection is unused should have been
3241     // eliminated by CallLeafPureNode::Ideal during IGVN.
3242     assert(n->as_CallLeafPure()->proj_out_or_null(TypeFunc::Parms) != nullptr,
3243            "unused CallLeafPureNode should have been removed before final graph reshaping");
3244   }
3245 #endif
3246   // Count FPU ops and common calls, implements item (3)
3247   bool gc_handled = BarrierSet::barrier_set()->barrier_set_c2()->final_graph_reshaping(this, n, nop, dead_nodes);
3248   if (!gc_handled) {
3249     final_graph_reshaping_main_switch(n, frc, nop, dead_nodes);
3250   }
3251 
3252   // Collect CFG split points
3253   if (n->is_MultiBranch() && !n->is_RangeCheck()) {
3254     frc._tests.push(n);
3255   }
3256 }
3257 
3258 void Compile::handle_div_mod_op(Node* n, BasicType bt, bool is_unsigned) {
3259   if (!UseDivMod) {
3260     return;
3261   }
3262 
3263   // Check if "a % b" and "a / b" both exist
3264   Node* d = n->find_similar(Op_DivIL(bt, is_unsigned));
3265   if (d == nullptr) {
3266     return;
3267   }
3268 
3269   // Replace them with a fused divmod if supported
3270   if (Matcher::has_match_rule(Op_DivModIL(bt, is_unsigned))) {
3271     DivModNode* divmod = DivModNode::make(n, bt, is_unsigned);
3272     // If the divisor input for a Div (or Mod etc.) is not zero, then the control input of the Div is set to zero.
3273     // It could be that the divisor input is found not zero because its type is narrowed down by a CastII in the
3274     // subgraph for that input. Range check CastIIs are removed during final graph reshape. To preserve the dependency
3275     // carried by a CastII, precedence edges are added to the Div node. We need to transfer the precedence edges to the
3276     // DivMod node so the dependency is not lost.
3277     divmod->add_prec_from(n);
3278     divmod->add_prec_from(d);
3279     d->subsume_by(divmod->div_proj(), this);
3280     n->subsume_by(divmod->mod_proj(), this);
3281   } else {
3282     // Replace "a % b" with "a - ((a / b) * b)"
3283     Node* mult = MulNode::make(d, d->in(2), bt);
3284     Node* sub = SubNode::make(d->in(1), mult, bt);
3285     n->subsume_by(sub, this);
3286   }
3287 }
3288 
3289 void Compile::final_graph_reshaping_main_switch(Node* n, Final_Reshape_Counts& frc, uint nop, Unique_Node_List& dead_nodes) {
3290   switch( nop ) {
3291   // Count all float operations that may use FPU
3292   case Op_AddHF:
3293   case Op_MulHF:
3294   case Op_AddF:
3295   case Op_SubF:
3296   case Op_MulF:
3297   case Op_DivF:
3298   case Op_NegF:
3299   case Op_ModF:
3300   case Op_ConvI2F:
3301   case Op_ConF:
3302   case Op_CmpF:
3303   case Op_CmpF3:
3304   case Op_StoreF:
3305   case Op_LoadF:
3306   // case Op_ConvL2F: // longs are split into 32-bit halves
3307     frc.inc_float_count();
3308     break;
3309 
3310   case Op_ConvF2D:
3311   case Op_ConvD2F:
3312     frc.inc_float_count();
3313     frc.inc_double_count();
3314     break;
3315 
3316   // Count all double operations that may use FPU
3317   case Op_AddD:
3318   case Op_SubD:
3319   case Op_MulD:
3320   case Op_DivD:
3321   case Op_NegD:
3322   case Op_ModD:
3323   case Op_ConvI2D:
3324   case Op_ConvD2I:
3325   // case Op_ConvL2D: // handled by leaf call
3326   // case Op_ConvD2L: // handled by leaf call
3327   case Op_ConD:
3328   case Op_CmpD:
3329   case Op_CmpD3:
3330   case Op_StoreD:
3331   case Op_LoadD:
3332   case Op_LoadD_unaligned:
3333     frc.inc_double_count();
3334     break;
3335   case Op_Opaque1:              // Remove Opaque Nodes before matching
3336     n->subsume_by(n->in(1), this);
3337     break;
3338   case Op_CallLeafPure: {
3339     // If the pure call is not supported, then lower to a CallLeaf.
3340     if (!Matcher::match_rule_supported(Op_CallLeafPure)) {
3341       CallNode* call = n->as_Call();
3342       CallNode* new_call = new CallLeafNode(call->tf(), call->entry_point(),
3343                                             call->_name, TypeRawPtr::BOTTOM);
3344       new_call->init_req(TypeFunc::Control, call->in(TypeFunc::Control));
3345       new_call->init_req(TypeFunc::I_O, C->top());
3346       new_call->init_req(TypeFunc::Memory, C->top());
3347       new_call->init_req(TypeFunc::ReturnAdr, C->top());
3348       new_call->init_req(TypeFunc::FramePtr, C->top());
3349       for (unsigned int i = TypeFunc::Parms; i < call->tf()->domain()->cnt(); i++) {
3350         new_call->init_req(i, call->in(i));
3351       }
3352       n->subsume_by(new_call, this);
3353     }
3354     frc.inc_call_count();
3355     break;
3356   }
3357   case Op_CallStaticJava:
3358   case Op_CallJava:
3359   case Op_CallDynamicJava:
3360     frc.inc_java_call_count(); // Count java call site;
3361   case Op_CallRuntime:
3362   case Op_CallLeaf:
3363   case Op_CallLeafVector:
3364   case Op_CallLeafNoFP: {
3365     assert (n->is_Call(), "");
3366     CallNode *call = n->as_Call();
3367     // Count call sites where the FP mode bit would have to be flipped.
3368     // Do not count uncommon runtime calls:
3369     // uncommon_trap, _complete_monitor_locking, _complete_monitor_unlocking,
3370     // _new_Java, _new_typeArray, _new_objArray, _rethrow_Java, ...
3371     if (!call->is_CallStaticJava() || !call->as_CallStaticJava()->_name) {
3372       frc.inc_call_count();   // Count the call site
3373     } else {                  // See if uncommon argument is shared
3374       Node *n = call->in(TypeFunc::Parms);
3375       int nop = n->Opcode();
3376       // Clone shared simple arguments to uncommon calls, item (1).
3377       if (n->outcnt() > 1 &&
3378           !n->is_Proj() &&
3379           nop != Op_CreateEx &&
3380           nop != Op_CheckCastPP &&
3381           nop != Op_DecodeN &&
3382           nop != Op_DecodeNKlass &&
3383           !n->is_Mem() &&
3384           !n->is_Phi()) {
3385         Node *x = n->clone();
3386         call->set_req(TypeFunc::Parms, x);
3387       }
3388     }
3389     break;
3390   }
3391   case Op_StoreB:
3392   case Op_StoreC:
3393   case Op_StoreI:
3394   case Op_StoreL:
3395   case Op_CompareAndSwapB:
3396   case Op_CompareAndSwapS:
3397   case Op_CompareAndSwapI:
3398   case Op_CompareAndSwapL:
3399   case Op_CompareAndSwapP:
3400   case Op_CompareAndSwapN:
3401   case Op_WeakCompareAndSwapB:
3402   case Op_WeakCompareAndSwapS:
3403   case Op_WeakCompareAndSwapI:
3404   case Op_WeakCompareAndSwapL:
3405   case Op_WeakCompareAndSwapP:
3406   case Op_WeakCompareAndSwapN:
3407   case Op_CompareAndExchangeB:
3408   case Op_CompareAndExchangeS:
3409   case Op_CompareAndExchangeI:
3410   case Op_CompareAndExchangeL:
3411   case Op_CompareAndExchangeP:
3412   case Op_CompareAndExchangeN:
3413   case Op_GetAndAddS:
3414   case Op_GetAndAddB:
3415   case Op_GetAndAddI:
3416   case Op_GetAndAddL:
3417   case Op_GetAndSetS:
3418   case Op_GetAndSetB:
3419   case Op_GetAndSetI:
3420   case Op_GetAndSetL:
3421   case Op_GetAndSetP:
3422   case Op_GetAndSetN:
3423   case Op_StoreP:
3424   case Op_StoreN:
3425   case Op_StoreNKlass:
3426   case Op_LoadB:
3427   case Op_LoadUB:
3428   case Op_LoadUS:
3429   case Op_LoadI:
3430   case Op_LoadKlass:
3431   case Op_LoadNKlass:
3432   case Op_LoadL:
3433   case Op_LoadL_unaligned:
3434   case Op_LoadP:
3435   case Op_LoadN:
3436   case Op_LoadRange:
3437   case Op_LoadS:
3438     break;
3439 
3440   case Op_AddP: {               // Assert sane base pointers
3441     Node *addp = n->in(AddPNode::Address);
3442     assert(n->as_AddP()->address_input_has_same_base(), "Base pointers must match (addp %u)", addp->_idx );
3443 #ifdef _LP64
3444     if (addp->Opcode() == Op_ConP &&
3445         addp == n->in(AddPNode::Base) &&
3446         n->in(AddPNode::Offset)->is_Con()) {
3447       // If the transformation of ConP to ConN+DecodeN is beneficial depends
3448       // on the platform and on the compressed oops mode.
3449       // Use addressing with narrow klass to load with offset on x86.
3450       // Some platforms can use the constant pool to load ConP.
3451       // Do this transformation here since IGVN will convert ConN back to ConP.
3452       const Type* t = addp->bottom_type();
3453       bool is_oop   = t->isa_oopptr() != nullptr;
3454       bool is_klass = t->isa_klassptr() != nullptr;
3455 
3456       if ((is_oop   && UseCompressedOops          && Matcher::const_oop_prefer_decode()  ) ||
3457           (is_klass && Matcher::const_klass_prefer_decode() &&
3458            t->isa_klassptr()->exact_klass()->is_in_encoding_range())) {
3459         Node* nn = nullptr;
3460 
3461         int op = is_oop ? Op_ConN : Op_ConNKlass;
3462 
3463         // Look for existing ConN node of the same exact type.
3464         Node* r  = root();
3465         uint cnt = r->outcnt();
3466         for (uint i = 0; i < cnt; i++) {
3467           Node* m = r->raw_out(i);
3468           if (m!= nullptr && m->Opcode() == op &&
3469               m->bottom_type()->make_ptr() == t) {
3470             nn = m;
3471             break;
3472           }
3473         }
3474         if (nn != nullptr) {
3475           // Decode a narrow oop to match address
3476           // [R12 + narrow_oop_reg<<3 + offset]
3477           if (is_oop) {
3478             nn = new DecodeNNode(nn, t);
3479           } else {
3480             nn = new DecodeNKlassNode(nn, t);
3481           }
3482           // Check for succeeding AddP which uses the same Base.
3483           // Otherwise we will run into the assertion above when visiting that guy.
3484           for (uint i = 0; i < n->outcnt(); ++i) {
3485             Node *out_i = n->raw_out(i);
3486             if (out_i && out_i->is_AddP() && out_i->in(AddPNode::Base) == addp) {
3487               out_i->set_req(AddPNode::Base, nn);
3488 #ifdef ASSERT
3489               for (uint j = 0; j < out_i->outcnt(); ++j) {
3490                 Node *out_j = out_i->raw_out(j);
3491                 assert(out_j == nullptr || !out_j->is_AddP() || out_j->in(AddPNode::Base) != addp,
3492                        "more than 2 AddP nodes in a chain (out_j %u)", out_j->_idx);
3493               }
3494 #endif
3495             }
3496           }
3497           n->set_req(AddPNode::Base, nn);
3498           n->set_req(AddPNode::Address, nn);
3499           if (addp->outcnt() == 0) {
3500             addp->disconnect_inputs(this);
3501           }
3502         }
3503       }
3504     }
3505 #endif
3506     break;
3507   }
3508 
3509   case Op_CastPP: {
3510     // Remove CastPP nodes to gain more freedom during scheduling but
3511     // keep the dependency they encode as control or precedence edges
3512     // (if control is set already) on memory operations. Some CastPP
3513     // nodes don't have a control (don't carry a dependency): skip
3514     // those.
3515     if (n->in(0) != nullptr) {
3516       ResourceMark rm;
3517       Unique_Node_List wq;
3518       wq.push(n);
3519       for (uint next = 0; next < wq.size(); ++next) {
3520         Node *m = wq.at(next);
3521         for (DUIterator_Fast imax, i = m->fast_outs(imax); i < imax; i++) {
3522           Node* use = m->fast_out(i);
3523           if (use->is_Mem() || use->is_EncodeNarrowPtr()) {
3524             use->ensure_control_or_add_prec(n->in(0));
3525           } else {
3526             switch(use->Opcode()) {
3527             case Op_AddP:
3528             case Op_DecodeN:
3529             case Op_DecodeNKlass:
3530             case Op_CheckCastPP:
3531             case Op_CastPP:
3532               wq.push(use);
3533               break;
3534             }
3535           }
3536         }
3537       }
3538     }
3539     const bool is_LP64 = LP64_ONLY(true) NOT_LP64(false);
3540     if (is_LP64 && n->in(1)->is_DecodeN() && Matcher::gen_narrow_oop_implicit_null_checks()) {
3541       Node* in1 = n->in(1);
3542       const Type* t = n->bottom_type();
3543       Node* new_in1 = in1->clone();
3544       new_in1->as_DecodeN()->set_type(t);
3545 
3546       if (!Matcher::narrow_oop_use_complex_address()) {
3547         //
3548         // x86, ARM and friends can handle 2 adds in addressing mode
3549         // and Matcher can fold a DecodeN node into address by using
3550         // a narrow oop directly and do implicit null check in address:
3551         //
3552         // [R12 + narrow_oop_reg<<3 + offset]
3553         // NullCheck narrow_oop_reg
3554         //
3555         // On other platforms (Sparc) we have to keep new DecodeN node and
3556         // use it to do implicit null check in address:
3557         //
3558         // decode_not_null narrow_oop_reg, base_reg
3559         // [base_reg + offset]
3560         // NullCheck base_reg
3561         //
3562         // Pin the new DecodeN node to non-null path on these platform (Sparc)
3563         // to keep the information to which null check the new DecodeN node
3564         // corresponds to use it as value in implicit_null_check().
3565         //
3566         new_in1->set_req(0, n->in(0));
3567       }
3568 
3569       n->subsume_by(new_in1, this);
3570       if (in1->outcnt() == 0) {
3571         in1->disconnect_inputs(this);
3572       }
3573     } else {
3574       n->subsume_by(n->in(1), this);
3575       if (n->outcnt() == 0) {
3576         n->disconnect_inputs(this);
3577       }
3578     }
3579     break;
3580   }
3581   case Op_CastII: {
3582     n->as_CastII()->remove_range_check_cast(this);
3583     break;
3584   }
3585 #ifdef _LP64
3586   case Op_CmpP:
3587     // Do this transformation here to preserve CmpPNode::sub() and
3588     // other TypePtr related Ideal optimizations (for example, ptr nullness).
3589     if (n->in(1)->is_DecodeNarrowPtr() || n->in(2)->is_DecodeNarrowPtr()) {
3590       Node* in1 = n->in(1);
3591       Node* in2 = n->in(2);
3592       if (!in1->is_DecodeNarrowPtr()) {
3593         in2 = in1;
3594         in1 = n->in(2);
3595       }
3596       assert(in1->is_DecodeNarrowPtr(), "sanity");
3597 
3598       Node* new_in2 = nullptr;
3599       if (in2->is_DecodeNarrowPtr()) {
3600         assert(in2->Opcode() == in1->Opcode(), "must be same node type");
3601         new_in2 = in2->in(1);
3602       } else if (in2->Opcode() == Op_ConP) {
3603         const Type* t = in2->bottom_type();
3604         if (t == TypePtr::NULL_PTR) {
3605           assert(in1->is_DecodeN(), "compare klass to null?");
3606           // Don't convert CmpP null check into CmpN if compressed
3607           // oops implicit null check is not generated.
3608           // This will allow to generate normal oop implicit null check.
3609           if (Matcher::gen_narrow_oop_implicit_null_checks())
3610             new_in2 = ConNode::make(TypeNarrowOop::NULL_PTR);
3611           //
3612           // This transformation together with CastPP transformation above
3613           // will generated code for implicit null checks for compressed oops.
3614           //
3615           // The original code after Optimize()
3616           //
3617           //    LoadN memory, narrow_oop_reg
3618           //    decode narrow_oop_reg, base_reg
3619           //    CmpP base_reg, nullptr
3620           //    CastPP base_reg // NotNull
3621           //    Load [base_reg + offset], val_reg
3622           //
3623           // after these transformations will be
3624           //
3625           //    LoadN memory, narrow_oop_reg
3626           //    CmpN narrow_oop_reg, nullptr
3627           //    decode_not_null narrow_oop_reg, base_reg
3628           //    Load [base_reg + offset], val_reg
3629           //
3630           // and the uncommon path (== nullptr) will use narrow_oop_reg directly
3631           // since narrow oops can be used in debug info now (see the code in
3632           // final_graph_reshaping_walk()).
3633           //
3634           // At the end the code will be matched to
3635           // on x86:
3636           //
3637           //    Load_narrow_oop memory, narrow_oop_reg
3638           //    Load [R12 + narrow_oop_reg<<3 + offset], val_reg
3639           //    NullCheck narrow_oop_reg
3640           //
3641           // and on sparc:
3642           //
3643           //    Load_narrow_oop memory, narrow_oop_reg
3644           //    decode_not_null narrow_oop_reg, base_reg
3645           //    Load [base_reg + offset], val_reg
3646           //    NullCheck base_reg
3647           //
3648         } else if (t->isa_oopptr()) {
3649           new_in2 = ConNode::make(t->make_narrowoop());
3650         } else if (t->isa_klassptr()) {
3651           ciKlass* klass = t->is_klassptr()->exact_klass();
3652           if (klass->is_in_encoding_range()) {
3653             new_in2 = ConNode::make(t->make_narrowklass());
3654           }
3655         }
3656       }
3657       if (new_in2 != nullptr) {
3658         Node* cmpN = new CmpNNode(in1->in(1), new_in2);
3659         n->subsume_by(cmpN, this);
3660         if (in1->outcnt() == 0) {
3661           in1->disconnect_inputs(this);
3662         }
3663         if (in2->outcnt() == 0) {
3664           in2->disconnect_inputs(this);
3665         }
3666       }
3667     }
3668     break;
3669 
3670   case Op_DecodeN:
3671   case Op_DecodeNKlass:
3672     assert(!n->in(1)->is_EncodeNarrowPtr(), "should be optimized out");
3673     // DecodeN could be pinned when it can't be fold into
3674     // an address expression, see the code for Op_CastPP above.
3675     assert(n->in(0) == nullptr || (UseCompressedOops && !Matcher::narrow_oop_use_complex_address()), "no control");
3676     break;
3677 
3678   case Op_EncodeP:
3679   case Op_EncodePKlass: {
3680     Node* in1 = n->in(1);
3681     if (in1->is_DecodeNarrowPtr()) {
3682       n->subsume_by(in1->in(1), this);
3683     } else if (in1->Opcode() == Op_ConP) {
3684       const Type* t = in1->bottom_type();
3685       if (t == TypePtr::NULL_PTR) {
3686         assert(t->isa_oopptr(), "null klass?");
3687         n->subsume_by(ConNode::make(TypeNarrowOop::NULL_PTR), this);
3688       } else if (t->isa_oopptr()) {
3689         n->subsume_by(ConNode::make(t->make_narrowoop()), this);
3690       } else if (t->isa_klassptr()) {
3691         ciKlass* klass = t->is_klassptr()->exact_klass();
3692         if (klass->is_in_encoding_range()) {
3693           n->subsume_by(ConNode::make(t->make_narrowklass()), this);
3694         } else {
3695           assert(false, "unencodable klass in ConP -> EncodeP");
3696           C->record_failure("unencodable klass in ConP -> EncodeP");
3697         }
3698       }
3699     }
3700     if (in1->outcnt() == 0) {
3701       in1->disconnect_inputs(this);
3702     }
3703     break;
3704   }
3705 
3706   case Op_Proj: {
3707     if (OptimizeStringConcat || IncrementalInline) {
3708       ProjNode* proj = n->as_Proj();
3709       if (proj->_is_io_use) {
3710         assert(proj->_con == TypeFunc::I_O || proj->_con == TypeFunc::Memory, "");
3711         // Separate projections were used for the exception path which
3712         // are normally removed by a late inline.  If it wasn't inlined
3713         // then they will hang around and should just be replaced with
3714         // the original one. Merge them.
3715         Node* non_io_proj = proj->in(0)->as_Multi()->proj_out_or_null(proj->_con, false /*is_io_use*/);
3716         if (non_io_proj  != nullptr) {
3717           proj->subsume_by(non_io_proj , this);
3718         }
3719       }
3720     }
3721     break;
3722   }
3723 
3724   case Op_Phi:
3725     if (n->as_Phi()->bottom_type()->isa_narrowoop() || n->as_Phi()->bottom_type()->isa_narrowklass()) {
3726       // The EncodeP optimization may create Phi with the same edges
3727       // for all paths. It is not handled well by Register Allocator.
3728       Node* unique_in = n->in(1);
3729       assert(unique_in != nullptr, "");
3730       uint cnt = n->req();
3731       for (uint i = 2; i < cnt; i++) {
3732         Node* m = n->in(i);
3733         assert(m != nullptr, "");
3734         if (unique_in != m)
3735           unique_in = nullptr;
3736       }
3737       if (unique_in != nullptr) {
3738         n->subsume_by(unique_in, this);
3739       }
3740     }
3741     break;
3742 
3743 #endif
3744 
3745   case Op_ModI:
3746     handle_div_mod_op(n, T_INT, false);
3747     break;
3748 
3749   case Op_ModL:
3750     handle_div_mod_op(n, T_LONG, false);
3751     break;
3752 
3753   case Op_UModI:
3754     handle_div_mod_op(n, T_INT, true);
3755     break;
3756 
3757   case Op_UModL:
3758     handle_div_mod_op(n, T_LONG, true);
3759     break;
3760 
3761   case Op_LoadVector:
3762   case Op_StoreVector:
3763 #ifdef ASSERT
3764     // Add VerifyVectorAlignment node between adr and load / store.
3765     if (VerifyAlignVector && Matcher::has_match_rule(Op_VerifyVectorAlignment)) {
3766       bool must_verify_alignment = n->is_LoadVector() ? n->as_LoadVector()->must_verify_alignment() :
3767                                                         n->as_StoreVector()->must_verify_alignment();
3768       if (must_verify_alignment) {
3769         jlong vector_width = n->is_LoadVector() ? n->as_LoadVector()->memory_size() :
3770                                                   n->as_StoreVector()->memory_size();
3771         // The memory access should be aligned to the vector width in bytes.
3772         // However, the underlying array is possibly less well aligned, but at least
3773         // to ObjectAlignmentInBytes. Hence, even if multiple arrays are accessed in
3774         // a loop we can expect at least the following alignment:
3775         jlong guaranteed_alignment = MIN2(vector_width, (jlong)ObjectAlignmentInBytes);
3776         assert(2 <= guaranteed_alignment && guaranteed_alignment <= 64, "alignment must be in range");
3777         assert(is_power_of_2(guaranteed_alignment), "alignment must be power of 2");
3778         // Create mask from alignment. e.g. 0b1000 -> 0b0111
3779         jlong mask = guaranteed_alignment - 1;
3780         Node* mask_con = ConLNode::make(mask);
3781         VerifyVectorAlignmentNode* va = new VerifyVectorAlignmentNode(n->in(MemNode::Address), mask_con);
3782         n->set_req(MemNode::Address, va);
3783       }
3784     }
3785 #endif
3786     break;
3787 
3788   case Op_LoadVectorGather:
3789   case Op_StoreVectorScatter:
3790   case Op_LoadVectorGatherMasked:
3791   case Op_StoreVectorScatterMasked:
3792   case Op_VectorCmpMasked:
3793   case Op_VectorMaskGen:
3794   case Op_LoadVectorMasked:
3795   case Op_StoreVectorMasked:
3796     break;
3797 
3798   case Op_AddReductionVI:
3799   case Op_AddReductionVL:
3800   case Op_AddReductionVHF:
3801   case Op_AddReductionVF:
3802   case Op_AddReductionVD:
3803   case Op_MulReductionVI:
3804   case Op_MulReductionVL:
3805   case Op_MulReductionVHF:
3806   case Op_MulReductionVF:
3807   case Op_MulReductionVD:
3808   case Op_MinReductionV:
3809   case Op_MaxReductionV:
3810   case Op_UMinReductionV:
3811   case Op_UMaxReductionV:
3812   case Op_AndReductionV:
3813   case Op_OrReductionV:
3814   case Op_XorReductionV:
3815     break;
3816 
3817   case Op_PackB:
3818   case Op_PackS:
3819   case Op_PackI:
3820   case Op_PackF:
3821   case Op_PackL:
3822   case Op_PackD:
3823     if (n->req()-1 > 2) {
3824       // Replace many operand PackNodes with a binary tree for matching
3825       PackNode* p = (PackNode*) n;
3826       Node* btp = p->binary_tree_pack(1, n->req());
3827       n->subsume_by(btp, this);
3828     }
3829     break;
3830   case Op_Loop:
3831     // When StressCountedLoop is enabled, this loop may intentionally avoid a counted loop conversion.
3832     // This is expected behavior for the stress mode, which exercises alternative compilation paths.
3833     if (!StressCountedLoop) {
3834       assert(!n->as_Loop()->is_loop_nest_inner_loop() || _loop_opts_cnt == 0, "should have been turned into a counted loop");
3835     }
3836   case Op_CountedLoop:
3837   case Op_LongCountedLoop:
3838   case Op_OuterStripMinedLoop:
3839     if (n->as_Loop()->is_inner_loop()) {
3840       frc.inc_inner_loop_count();
3841     }
3842     n->as_Loop()->verify_strip_mined(0);
3843     break;
3844   case Op_LShiftI:
3845   case Op_RShiftI:
3846   case Op_URShiftI:
3847   case Op_LShiftL:
3848   case Op_RShiftL:
3849   case Op_URShiftL:
3850     if (Matcher::need_masked_shift_count) {
3851       // The cpu's shift instructions don't restrict the count to the
3852       // lower 5/6 bits. We need to do the masking ourselves.
3853       Node* in2 = n->in(2);
3854       juint mask = (n->bottom_type() == TypeInt::INT) ? (BitsPerInt - 1) : (BitsPerLong - 1);
3855       const TypeInt* t = in2->find_int_type();
3856       if (t != nullptr && t->is_con()) {
3857         juint shift = t->get_con();
3858         if (shift > mask) { // Unsigned cmp
3859           n->set_req(2, ConNode::make(TypeInt::make(shift & mask)));
3860         }
3861       } else {
3862         if (t == nullptr || t->_lo < 0 || t->_hi > (int)mask) {
3863           Node* shift = new AndINode(in2, ConNode::make(TypeInt::make(mask)));
3864           n->set_req(2, shift);
3865         }
3866       }
3867       if (in2->outcnt() == 0) { // Remove dead node
3868         in2->disconnect_inputs(this);
3869       }
3870     }
3871     break;
3872   case Op_MemBarStoreStore:
3873   case Op_MemBarRelease:
3874     // Break the link with AllocateNode: it is no longer useful and
3875     // confuses register allocation.
3876     if (n->req() > MemBarNode::Precedent) {
3877       n->set_req(MemBarNode::Precedent, top());
3878     }
3879     break;
3880   case Op_MemBarAcquire: {
3881     if (n->as_MemBar()->trailing_load() && n->req() > MemBarNode::Precedent) {
3882       // At parse time, the trailing MemBarAcquire for a volatile load
3883       // is created with an edge to the load. After optimizations,
3884       // that input may be a chain of Phis. If those phis have no
3885       // other use, then the MemBarAcquire keeps them alive and
3886       // register allocation can be confused.
3887       dead_nodes.push(n->in(MemBarNode::Precedent));
3888       n->set_req(MemBarNode::Precedent, top());
3889     }
3890     break;
3891   }
3892   case Op_Blackhole:
3893     break;
3894   case Op_RangeCheck: {
3895     RangeCheckNode* rc = n->as_RangeCheck();
3896     Node* iff = new IfNode(rc->in(0), rc->in(1), rc->_prob, rc->_fcnt);
3897     n->subsume_by(iff, this);
3898     frc._tests.push(iff);
3899     break;
3900   }
3901   case Op_ConvI2L: {
3902     if (!Matcher::convi2l_type_required) {
3903       // Code generation on some platforms doesn't need accurate
3904       // ConvI2L types. Widening the type can help remove redundant
3905       // address computations.
3906       n->as_Type()->set_type(TypeLong::INT);
3907       ResourceMark rm;
3908       Unique_Node_List wq;
3909       wq.push(n);
3910       for (uint next = 0; next < wq.size(); next++) {
3911         Node *m = wq.at(next);
3912 
3913         for(;;) {
3914           // Loop over all nodes with identical inputs edges as m
3915           Node* k = m->find_similar(m->Opcode());
3916           if (k == nullptr) {
3917             break;
3918           }
3919           // Push their uses so we get a chance to remove node made
3920           // redundant
3921           for (DUIterator_Fast imax, i = k->fast_outs(imax); i < imax; i++) {
3922             Node* u = k->fast_out(i);
3923             if (u->Opcode() == Op_LShiftL ||
3924                 u->Opcode() == Op_AddL ||
3925                 u->Opcode() == Op_SubL ||
3926                 u->Opcode() == Op_AddP) {
3927               wq.push(u);
3928             }
3929           }
3930           // Replace all nodes with identical edges as m with m
3931           k->subsume_by(m, this);
3932         }
3933       }
3934     }
3935     break;
3936   }
3937   case Op_CmpUL: {
3938     if (!Matcher::has_match_rule(Op_CmpUL)) {
3939       // No support for unsigned long comparisons
3940       ConINode* sign_pos = new ConINode(TypeInt::make(BitsPerLong - 1));
3941       Node* sign_bit_mask = new RShiftLNode(n->in(1), sign_pos);
3942       Node* orl = new OrLNode(n->in(1), sign_bit_mask);
3943       ConLNode* remove_sign_mask = new ConLNode(TypeLong::make(max_jlong));
3944       Node* andl = new AndLNode(orl, remove_sign_mask);
3945       Node* cmp = new CmpLNode(andl, n->in(2));
3946       n->subsume_by(cmp, this);
3947     }
3948     break;
3949   }
3950 #ifdef ASSERT
3951   case Op_ConNKlass: {
3952     const TypePtr* tp = n->as_Type()->type()->make_ptr();
3953     ciKlass* klass = tp->is_klassptr()->exact_klass();
3954     assert(klass->is_in_encoding_range(), "klass cannot be compressed");
3955     break;
3956   }
3957 #endif
3958   default:
3959     assert(!n->is_Call(), "");
3960     assert(!n->is_Mem(), "");
3961     assert(nop != Op_ProfileBoolean, "should be eliminated during IGVN");
3962     break;
3963   }
3964 }
3965 
3966 //------------------------------final_graph_reshaping_walk---------------------
3967 // Replacing Opaque nodes with their input in final_graph_reshaping_impl(),
3968 // requires that the walk visits a node's inputs before visiting the node.
3969 void Compile::final_graph_reshaping_walk(Node_Stack& nstack, Node* root, Final_Reshape_Counts& frc, Unique_Node_List& dead_nodes) {
3970   Unique_Node_List sfpt;
3971 
3972   frc._visited.set(root->_idx); // first, mark node as visited
3973   uint cnt = root->req();
3974   Node *n = root;
3975   uint  i = 0;
3976   while (true) {
3977     if (i < cnt) {
3978       // Place all non-visited non-null inputs onto stack
3979       Node* m = n->in(i);
3980       ++i;
3981       if (m != nullptr && !frc._visited.test_set(m->_idx)) {
3982         if (m->is_SafePoint() && m->as_SafePoint()->jvms() != nullptr) {
3983           // compute worst case interpreter size in case of a deoptimization
3984           update_interpreter_frame_size(m->as_SafePoint()->jvms()->interpreter_frame_size());
3985 
3986           sfpt.push(m);
3987         }
3988         cnt = m->req();
3989         nstack.push(n, i); // put on stack parent and next input's index
3990         n = m;
3991         i = 0;
3992       }
3993     } else {
3994       // Now do post-visit work
3995       final_graph_reshaping_impl(n, frc, dead_nodes);
3996       if (nstack.is_empty())
3997         break;             // finished
3998       n = nstack.node();   // Get node from stack
3999       cnt = n->req();
4000       i = nstack.index();
4001       nstack.pop();        // Shift to the next node on stack
4002     }
4003   }
4004 
4005   expand_reachability_edges(sfpt);
4006 
4007   // Skip next transformation if compressed oops are not used.
4008   if (UseCompressedOops && !Matcher::gen_narrow_oop_implicit_null_checks())
4009     return;
4010 
4011   // Go over ReachabilityFence nodes to skip DecodeN nodes for referents.
4012   // The sole purpose of RF node is to keep the referent oop alive and
4013   // decoding the oop for that is not needed.
4014   for (int i = 0; i < C->reachability_fences_count(); i++) {
4015     ReachabilityFenceNode* rf = C->reachability_fence(i);
4016     DecodeNNode* dn = rf->in(1)->isa_DecodeN();
4017     if (dn != nullptr) {
4018       if (!dn->has_non_debug_uses() || Matcher::narrow_oop_use_complex_address()) {
4019         rf->set_req(1, dn->in(1));
4020         if (dn->outcnt() == 0) {
4021           dn->disconnect_inputs(this);
4022         }
4023       }
4024     }
4025   }
4026 
4027   // Go over safepoints nodes to skip DecodeN/DecodeNKlass nodes for debug edges.
4028   // It could be done for an uncommon traps or any safepoints/calls
4029   // if the DecodeN/DecodeNKlass node is referenced only in a debug info.
4030   while (sfpt.size() > 0) {
4031     n = sfpt.pop();
4032     JVMState *jvms = n->as_SafePoint()->jvms();
4033     assert(jvms != nullptr, "sanity");
4034     int start = jvms->debug_start();
4035     int end   = n->req();
4036     bool is_uncommon = (n->is_CallStaticJava() &&
4037                         n->as_CallStaticJava()->uncommon_trap_request() != 0);
4038     for (int j = start; j < end; j++) {
4039       Node* in = n->in(j);
4040       if (in->is_DecodeNarrowPtr() && (is_uncommon || !in->has_non_debug_uses())) {
4041         n->set_req(j, in->in(1));
4042         if (in->outcnt() == 0) {
4043           in->disconnect_inputs(this);
4044         }
4045       }
4046     }
4047   }
4048 }
4049 
4050 //------------------------------final_graph_reshaping--------------------------
4051 // Final Graph Reshaping.
4052 //
4053 // (1) Clone simple inputs to uncommon calls, so they can be scheduled late
4054 //     and not commoned up and forced early.  Must come after regular
4055 //     optimizations to avoid GVN undoing the cloning.  Clone constant
4056 //     inputs to Loop Phis; these will be split by the allocator anyways.
4057 //     Remove Opaque nodes.
4058 // (2) Move last-uses by commutative operations to the left input to encourage
4059 //     Intel update-in-place two-address operations and better register usage
4060 //     on RISCs.  Must come after regular optimizations to avoid GVN Ideal
4061 //     calls canonicalizing them back.
4062 // (3) Count the number of double-precision FP ops, single-precision FP ops
4063 //     and call sites.  On Intel, we can get correct rounding either by
4064 //     forcing singles to memory (requires extra stores and loads after each
4065 //     FP bytecode) or we can set a rounding mode bit (requires setting and
4066 //     clearing the mode bit around call sites).  The mode bit is only used
4067 //     if the relative frequency of single FP ops to calls is low enough.
4068 //     This is a key transform for SPEC mpeg_audio.
4069 // (4) Detect infinite loops; blobs of code reachable from above but not
4070 //     below.  Several of the Code_Gen algorithms fail on such code shapes,
4071 //     so we simply bail out.  Happens a lot in ZKM.jar, but also happens
4072 //     from time to time in other codes (such as -Xcomp finalizer loops, etc).
4073 //     Detection is by looking for IfNodes where only 1 projection is
4074 //     reachable from below or CatchNodes missing some targets.
4075 // (5) Assert for insane oop offsets in debug mode.
4076 
4077 bool Compile::final_graph_reshaping() {
4078   // an infinite loop may have been eliminated by the optimizer,
4079   // in which case the graph will be empty.
4080   if (root()->req() == 1) {
4081     // Do not compile method that is only a trivial infinite loop,
4082     // since the content of the loop may have been eliminated.
4083     record_method_not_compilable("trivial infinite loop");
4084     return true;
4085   }
4086 
4087   // Expensive nodes have their control input set to prevent the GVN
4088   // from freely commoning them. There's no GVN beyond this point so
4089   // no need to keep the control input. We want the expensive nodes to
4090   // be freely moved to the least frequent code path by gcm.
4091   assert(OptimizeExpensiveOps || expensive_count() == 0, "optimization off but list non empty?");
4092   for (int i = 0; i < expensive_count(); i++) {
4093     _expensive_nodes.at(i)->set_req(0, nullptr);
4094   }
4095 
4096   Final_Reshape_Counts frc;
4097 
4098   // Visit everybody reachable!
4099   // Allocate stack of size C->live_nodes()/2 to avoid frequent realloc
4100   Node_Stack nstack(live_nodes() >> 1);
4101   Unique_Node_List dead_nodes;
4102   final_graph_reshaping_walk(nstack, root(), frc, dead_nodes);
4103 
4104   // Check for unreachable (from below) code (i.e., infinite loops).
4105   for( uint i = 0; i < frc._tests.size(); i++ ) {
4106     MultiBranchNode *n = frc._tests[i]->as_MultiBranch();
4107     // Get number of CFG targets.
4108     // Note that PCTables include exception targets after calls.
4109     uint required_outcnt = n->required_outcnt();
4110     if (n->outcnt() != required_outcnt) {
4111       // Check for a few special cases.  Rethrow Nodes never take the
4112       // 'fall-thru' path, so expected kids is 1 less.
4113       if (n->is_PCTable() && n->in(0) && n->in(0)->in(0)) {
4114         if (n->in(0)->in(0)->is_Call()) {
4115           CallNode* call = n->in(0)->in(0)->as_Call();
4116           if (call->entry_point() == OptoRuntime::rethrow_stub()) {
4117             required_outcnt--;      // Rethrow always has 1 less kid
4118           } else if (call->req() > TypeFunc::Parms &&
4119                      call->is_CallDynamicJava()) {
4120             // Check for null receiver. In such case, the optimizer has
4121             // detected that the virtual call will always result in a null
4122             // pointer exception. The fall-through projection of this CatchNode
4123             // will not be populated.
4124             Node* arg0 = call->in(TypeFunc::Parms);
4125             if (arg0->is_Type() &&
4126                 arg0->as_Type()->type()->higher_equal(TypePtr::NULL_PTR)) {
4127               required_outcnt--;
4128             }
4129           } else if (call->entry_point() == OptoRuntime::new_array_Java() ||
4130                      call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4131             // Check for illegal array length. In such case, the optimizer has
4132             // detected that the allocation attempt will always result in an
4133             // exception. There is no fall-through projection of this CatchNode .
4134             assert(call->is_CallStaticJava(), "static call expected");
4135             assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4136             uint valid_length_test_input = call->req() - 1;
4137             Node* valid_length_test = call->in(valid_length_test_input);
4138             call->del_req(valid_length_test_input);
4139             if (valid_length_test->find_int_con(1) == 0) {
4140               required_outcnt--;
4141             }
4142             dead_nodes.push(valid_length_test);
4143             assert(n->outcnt() == required_outcnt, "malformed control flow");
4144             continue;
4145           }
4146         }
4147       }
4148 
4149       // Recheck with a better notion of 'required_outcnt'
4150       if (n->outcnt() != required_outcnt) {
4151         record_method_not_compilable("malformed control flow");
4152         return true;            // Not all targets reachable!
4153       }
4154     } else if (n->is_PCTable() && n->in(0) && n->in(0)->in(0) && n->in(0)->in(0)->is_Call()) {
4155       CallNode* call = n->in(0)->in(0)->as_Call();
4156       if (call->entry_point() == OptoRuntime::new_array_Java() ||
4157           call->entry_point() == OptoRuntime::new_array_nozero_Java()) {
4158         assert(call->is_CallStaticJava(), "static call expected");
4159         assert(call->req() == call->jvms()->endoff() + 1, "missing extra input");
4160         uint valid_length_test_input = call->req() - 1;
4161         dead_nodes.push(call->in(valid_length_test_input));
4162         call->del_req(valid_length_test_input); // valid length test useless now
4163       }
4164     }
4165     // Check that I actually visited all kids.  Unreached kids
4166     // must be infinite loops.
4167     for (DUIterator_Fast jmax, j = n->fast_outs(jmax); j < jmax; j++)
4168       if (!frc._visited.test(n->fast_out(j)->_idx)) {
4169         record_method_not_compilable("infinite loop");
4170         return true;            // Found unvisited kid; must be unreach
4171       }
4172 
4173     // Here so verification code in final_graph_reshaping_walk()
4174     // always see an OuterStripMinedLoopEnd
4175     if (n->is_OuterStripMinedLoopEnd() || n->is_LongCountedLoopEnd()) {
4176       IfNode* init_iff = n->as_If();
4177       Node* iff = new IfNode(init_iff->in(0), init_iff->in(1), init_iff->_prob, init_iff->_fcnt);
4178       n->subsume_by(iff, this);
4179     }
4180   }
4181 
4182   while (dead_nodes.size() > 0) {
4183     Node* m = dead_nodes.pop();
4184     if (m->outcnt() == 0 && m != top()) {
4185       for (uint j = 0; j < m->req(); j++) {
4186         Node* in = m->in(j);
4187         if (in != nullptr) {
4188           dead_nodes.push(in);
4189         }
4190       }
4191       m->disconnect_inputs(this);
4192     }
4193   }
4194 
4195   set_java_calls(frc.get_java_call_count());
4196   set_inner_loops(frc.get_inner_loop_count());
4197 
4198   // No infinite loops, no reason to bail out.
4199   return false;
4200 }
4201 
4202 //-----------------------------too_many_traps----------------------------------
4203 // Report if there are too many traps at the current method and bci.
4204 // Return true if there was a trap, and/or PerMethodTrapLimit is exceeded.
4205 bool Compile::too_many_traps(ciMethod* method,
4206                              int bci,
4207                              Deoptimization::DeoptReason reason) {
4208   ciMethodData* md = method->method_data();
4209   if (md->is_empty()) {
4210     // Assume the trap has not occurred, or that it occurred only
4211     // because of a transient condition during start-up in the interpreter.
4212     return false;
4213   }
4214   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4215   if (md->has_trap_at(bci, m, reason) != 0) {
4216     // Assume PerBytecodeTrapLimit==0, for a more conservative heuristic.
4217     // Also, if there are multiple reasons, or if there is no per-BCI record,
4218     // assume the worst.
4219     if (log())
4220       log()->elem("observe trap='%s' count='%d'",
4221                   Deoptimization::trap_reason_name(reason),
4222                   md->trap_count(reason));
4223     return true;
4224   } else {
4225     // Ignore method/bci and see if there have been too many globally.
4226     return too_many_traps(reason, md);
4227   }
4228 }
4229 
4230 // Less-accurate variant which does not require a method and bci.
4231 bool Compile::too_many_traps(Deoptimization::DeoptReason reason,
4232                              ciMethodData* logmd) {
4233   if (trap_count(reason) >= Deoptimization::per_method_trap_limit(reason)) {
4234     // Too many traps globally.
4235     // Note that we use cumulative trap_count, not just md->trap_count.
4236     if (log()) {
4237       int mcount = (logmd == nullptr)? -1: (int)logmd->trap_count(reason);
4238       log()->elem("observe trap='%s' count='0' mcount='%d' ccount='%d'",
4239                   Deoptimization::trap_reason_name(reason),
4240                   mcount, trap_count(reason));
4241     }
4242     return true;
4243   } else {
4244     // The coast is clear.
4245     return false;
4246   }
4247 }
4248 
4249 //--------------------------too_many_recompiles--------------------------------
4250 // Report if there are too many recompiles at the current method and bci.
4251 // Consults PerBytecodeRecompilationCutoff and PerMethodRecompilationCutoff.
4252 // Is not eager to return true, since this will cause the compiler to use
4253 // Action_none for a trap point, to avoid too many recompilations.
4254 bool Compile::too_many_recompiles(ciMethod* method,
4255                                   int bci,
4256                                   Deoptimization::DeoptReason reason) {
4257   ciMethodData* md = method->method_data();
4258   if (md->is_empty()) {
4259     // Assume the trap has not occurred, or that it occurred only
4260     // because of a transient condition during start-up in the interpreter.
4261     return false;
4262   }
4263   // Pick a cutoff point well within PerBytecodeRecompilationCutoff.
4264   uint bc_cutoff = (uint) PerBytecodeRecompilationCutoff / 8;
4265   uint m_cutoff  = (uint) PerMethodRecompilationCutoff / 2 + 1;  // not zero
4266   Deoptimization::DeoptReason per_bc_reason
4267     = Deoptimization::reason_recorded_per_bytecode_if_any(reason);
4268   ciMethod* m = Deoptimization::reason_is_speculate(reason) ? this->method() : nullptr;
4269   if ((per_bc_reason == Deoptimization::Reason_none
4270        || md->has_trap_at(bci, m, reason) != 0)
4271       // The trap frequency measure we care about is the recompile count:
4272       && md->trap_recompiled_at(bci, m)
4273       && md->overflow_recompile_count() >= bc_cutoff) {
4274     // Do not emit a trap here if it has already caused recompilations.
4275     // Also, if there are multiple reasons, or if there is no per-BCI record,
4276     // assume the worst.
4277     if (log())
4278       log()->elem("observe trap='%s recompiled' count='%d' recompiles2='%d'",
4279                   Deoptimization::trap_reason_name(reason),
4280                   md->trap_count(reason),
4281                   md->overflow_recompile_count());
4282     return true;
4283   } else if (trap_count(reason) != 0
4284              && decompile_count() >= m_cutoff) {
4285     // Too many recompiles globally, and we have seen this sort of trap.
4286     // Use cumulative decompile_count, not just md->decompile_count.
4287     if (log())
4288       log()->elem("observe trap='%s' count='%d' mcount='%d' decompiles='%d' mdecompiles='%d'",
4289                   Deoptimization::trap_reason_name(reason),
4290                   md->trap_count(reason), trap_count(reason),
4291                   md->decompile_count(), decompile_count());
4292     return true;
4293   } else {
4294     // The coast is clear.
4295     return false;
4296   }
4297 }
4298 
4299 // Compute when not to trap. Used by matching trap based nodes and
4300 // NullCheck optimization.
4301 void Compile::set_allowed_deopt_reasons() {
4302   _allowed_reasons = 0;
4303   if (is_method_compilation()) {
4304     for (int rs = (int)Deoptimization::Reason_none+1; rs < Compile::trapHistLength; rs++) {
4305       assert(rs < BitsPerInt, "recode bit map");
4306       if (!too_many_traps((Deoptimization::DeoptReason) rs)) {
4307         _allowed_reasons |= nth_bit(rs);
4308       }
4309     }
4310   }
4311 }
4312 
4313 bool Compile::needs_clinit_barrier(ciMethod* method, ciMethod* accessing_method) {
4314   return method->is_static() && needs_clinit_barrier(method->holder(), accessing_method);
4315 }
4316 
4317 bool Compile::needs_clinit_barrier(ciField* field, ciMethod* accessing_method) {
4318   return field->is_static() && needs_clinit_barrier(field->holder(), accessing_method);
4319 }
4320 
4321 bool Compile::needs_clinit_barrier(ciInstanceKlass* holder, ciMethod* accessing_method) {
4322   if (holder->is_initialized()) {
4323     return false;
4324   }
4325   if (holder->is_being_initialized()) {
4326     if (accessing_method->holder() == holder) {
4327       // Access inside a class. The barrier can be elided when access happens in <clinit>,
4328       // <init>, or a static method. In all those cases, there was an initialization
4329       // barrier on the holder klass passed.
4330       if (accessing_method->is_static_initializer() ||
4331           accessing_method->is_object_initializer() ||
4332           accessing_method->is_static()) {
4333         return false;
4334       }
4335     } else if (accessing_method->holder()->is_subclass_of(holder)) {
4336       // Access from a subclass. The barrier can be elided only when access happens in <clinit>.
4337       // In case of <init> or a static method, the barrier is on the subclass is not enough:
4338       // child class can become fully initialized while its parent class is still being initialized.
4339       if (accessing_method->is_static_initializer()) {
4340         return false;
4341       }
4342     }
4343     ciMethod* root = method(); // the root method of compilation
4344     if (root != accessing_method) {
4345       return needs_clinit_barrier(holder, root); // check access in the context of compilation root
4346     }
4347   }
4348   return true;
4349 }
4350 
4351 #ifndef PRODUCT
4352 //------------------------------verify_bidirectional_edges---------------------
4353 // For each input edge to a node (ie - for each Use-Def edge), verify that
4354 // there is a corresponding Def-Use edge.
4355 void Compile::verify_bidirectional_edges(Unique_Node_List& visited, const Unique_Node_List* root_and_safepoints) const {
4356   // Allocate stack of size C->live_nodes()/16 to avoid frequent realloc
4357   uint stack_size = live_nodes() >> 4;
4358   Node_List nstack(MAX2(stack_size, (uint) OptoNodeListSize));
4359   if (root_and_safepoints != nullptr) {
4360     assert(root_and_safepoints->member(_root), "root is not in root_and_safepoints");
4361     for (uint i = 0, limit = root_and_safepoints->size(); i < limit; i++) {
4362       Node* root_or_safepoint = root_and_safepoints->at(i);
4363       // If the node is a safepoint, let's check if it still has a control input
4364       // Lack of control input signifies that this node was killed by CCP or
4365       // recursively by remove_globally_dead_node and it shouldn't be a starting
4366       // point.
4367       if (!root_or_safepoint->is_SafePoint() || root_or_safepoint->in(0) != nullptr) {
4368         nstack.push(root_or_safepoint);
4369       }
4370     }
4371   } else {
4372     nstack.push(_root);
4373   }
4374 
4375   while (nstack.size() > 0) {
4376     Node* n = nstack.pop();
4377     if (visited.member(n)) {
4378       continue;
4379     }
4380     visited.push(n);
4381 
4382     // Walk over all input edges, checking for correspondence
4383     uint length = n->len();
4384     for (uint i = 0; i < length; i++) {
4385       Node* in = n->in(i);
4386       if (in != nullptr && !visited.member(in)) {
4387         nstack.push(in); // Put it on stack
4388       }
4389       if (in != nullptr && !in->is_top()) {
4390         // Count instances of `next`
4391         int cnt = 0;
4392         for (uint idx = 0; idx < in->_outcnt; idx++) {
4393           if (in->_out[idx] == n) {
4394             cnt++;
4395           }
4396         }
4397         assert(cnt > 0, "Failed to find Def-Use edge.");
4398         // Check for duplicate edges
4399         // walk the input array downcounting the input edges to n
4400         for (uint j = 0; j < length; j++) {
4401           if (n->in(j) == in) {
4402             cnt--;
4403           }
4404         }
4405         assert(cnt == 0, "Mismatched edge count.");
4406       } else if (in == nullptr) {
4407         assert(i == 0 || i >= n->req() ||
4408                n->is_Region() || n->is_Phi() || n->is_ArrayCopy() ||
4409                (n->is_Unlock() && i == (n->req() - 1)) ||
4410                (n->is_MemBar() && i == 5), // the precedence edge to a membar can be removed during macro node expansion
4411               "only region, phi, arraycopy, unlock or membar nodes have null data edges");
4412       } else {
4413         assert(in->is_top(), "sanity");
4414         // Nothing to check.
4415       }
4416     }
4417   }
4418 }
4419 
4420 //------------------------------verify_graph_edges---------------------------
4421 // Walk the Graph and verify that there is a one-to-one correspondence
4422 // between Use-Def edges and Def-Use edges in the graph.
4423 void Compile::verify_graph_edges(bool no_dead_code, const Unique_Node_List* root_and_safepoints) const {
4424   if (VerifyGraphEdges) {
4425     Unique_Node_List visited;
4426 
4427     // Call graph walk to check edges
4428     verify_bidirectional_edges(visited, root_and_safepoints);
4429     if (no_dead_code) {
4430       // Now make sure that no visited node is used by an unvisited node.
4431       bool dead_nodes = false;
4432       Unique_Node_List checked;
4433       while (visited.size() > 0) {
4434         Node* n = visited.pop();
4435         checked.push(n);
4436         for (uint i = 0; i < n->outcnt(); i++) {
4437           Node* use = n->raw_out(i);
4438           if (checked.member(use))  continue;  // already checked
4439           if (visited.member(use))  continue;  // already in the graph
4440           if (use->is_Con())        continue;  // a dead ConNode is OK
4441           // At this point, we have found a dead node which is DU-reachable.
4442           if (!dead_nodes) {
4443             tty->print_cr("*** Dead nodes reachable via DU edges:");
4444             dead_nodes = true;
4445           }
4446           use->dump(2);
4447           tty->print_cr("---");
4448           checked.push(use);  // No repeats; pretend it is now checked.
4449         }
4450       }
4451       assert(!dead_nodes, "using nodes must be reachable from root");
4452     }
4453   }
4454 }
4455 #endif
4456 
4457 // The Compile object keeps track of failure reasons separately from the ciEnv.
4458 // This is required because there is not quite a 1-1 relation between the
4459 // ciEnv and its compilation task and the Compile object.  Note that one
4460 // ciEnv might use two Compile objects, if C2Compiler::compile_method decides
4461 // to backtrack and retry without subsuming loads.  Other than this backtracking
4462 // behavior, the Compile's failure reason is quietly copied up to the ciEnv
4463 // by the logic in C2Compiler.
4464 void Compile::record_failure(const char* reason DEBUG_ONLY(COMMA bool allow_multiple_failures)) {
4465   if (log() != nullptr) {
4466     log()->elem("failure reason='%s' phase='compile'", reason);
4467   }
4468   if (_failure_reason.get() == nullptr) {
4469     // Record the first failure reason.
4470     _failure_reason.set(reason);
4471     if (CaptureBailoutInformation) {
4472       _first_failure_details = new CompilationFailureInfo(reason);
4473     }
4474   } else {
4475     assert(!StressBailout || allow_multiple_failures, "should have handled previous failure.");
4476   }
4477 
4478   if (!C->failure_reason_is(C2Compiler::retry_no_subsuming_loads())) {
4479     C->print_method(PHASE_FAILURE, 1);
4480   }
4481   _root = nullptr;  // flush the graph, too
4482 }
4483 
4484 Compile::TracePhase::TracePhase(const char* name, PhaseTraceId id)
4485   : TraceTime(name, &Phase::timers[id], CITime, CITimeVerbose),
4486     _compile(Compile::current()),
4487     _log(nullptr),
4488     _dolog(CITimeVerbose)
4489 {
4490   assert(_compile != nullptr, "sanity check");
4491   assert(id != PhaseTraceId::_t_none, "Don't use none");
4492   if (_dolog) {
4493     _log = _compile->log();
4494   }
4495   if (_log != nullptr) {
4496     _log->begin_head("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4497     _log->stamp();
4498     _log->end_head();
4499   }
4500 
4501   // Inform memory statistic, if enabled
4502   if (CompilationMemoryStatistic::enabled()) {
4503     CompilationMemoryStatistic::on_phase_start((int)id, name);
4504   }
4505 }
4506 
4507 Compile::TracePhase::TracePhase(PhaseTraceId id)
4508   : TracePhase(Phase::get_phase_trace_id_text(id), id) {}
4509 
4510 Compile::TracePhase::~TracePhase() {
4511 
4512   // Inform memory statistic, if enabled
4513   if (CompilationMemoryStatistic::enabled()) {
4514     CompilationMemoryStatistic::on_phase_end();
4515   }
4516 
4517   if (_compile->failing_internal()) {
4518     if (_log != nullptr) {
4519       _log->done("phase");
4520     }
4521     return; // timing code, not stressing bailouts.
4522   }
4523 #ifdef ASSERT
4524   if (PrintIdealNodeCount) {
4525     tty->print_cr("phase name='%s' nodes='%d' live='%d' live_graph_walk='%d'",
4526                   phase_name(), _compile->unique(), _compile->live_nodes(), _compile->count_live_nodes_by_graph_walk());
4527   }
4528 
4529   if (VerifyIdealNodeCount) {
4530     _compile->print_missing_nodes();
4531   }
4532 #endif
4533 
4534   if (_log != nullptr) {
4535     _log->done("phase name='%s' nodes='%d' live='%d'", phase_name(), _compile->unique(), _compile->live_nodes());
4536   }
4537 }
4538 
4539 //----------------------------static_subtype_check-----------------------------
4540 // Shortcut important common cases when superklass is exact:
4541 // (0) superklass is java.lang.Object (can occur in reflective code)
4542 // (1) subklass is already limited to a subtype of superklass => always ok
4543 // (2) subklass does not overlap with superklass => always fail
4544 // (3) superklass has NO subtypes and we can check with a simple compare.
4545 Compile::SubTypeCheckResult Compile::static_subtype_check(const TypeKlassPtr* superk, const TypeKlassPtr* subk, bool skip) {
4546   if (skip) {
4547     return SSC_full_test;       // Let caller generate the general case.
4548   }
4549 
4550   if (subk->is_java_subtype_of(superk)) {
4551     return SSC_always_true; // (0) and (1)  this test cannot fail
4552   }
4553 
4554   if (!subk->maybe_java_subtype_of(superk)) {
4555     return SSC_always_false; // (2) true path dead; no dynamic test needed
4556   }
4557 
4558   const Type* superelem = superk;
4559   if (superk->isa_aryklassptr()) {
4560     int ignored;
4561     superelem = superk->is_aryklassptr()->base_element_type(ignored);
4562   }
4563 
4564   if (superelem->isa_instklassptr()) {
4565     ciInstanceKlass* ik = superelem->is_instklassptr()->instance_klass();
4566     if (!ik->has_subklass()) {
4567       if (!ik->is_final()) {
4568         // Add a dependency if there is a chance of a later subclass.
4569         dependencies()->assert_leaf_type(ik);
4570       }
4571       if (!superk->maybe_java_subtype_of(subk)) {
4572         return SSC_always_false;
4573       }
4574       return SSC_easy_test;     // (3) caller can do a simple ptr comparison
4575     }
4576   } else {
4577     // A primitive array type has no subtypes.
4578     return SSC_easy_test;       // (3) caller can do a simple ptr comparison
4579   }
4580 
4581   return SSC_full_test;
4582 }
4583 
4584 Node* Compile::conv_I2X_index(PhaseGVN* phase, Node* idx, const TypeInt* sizetype, Node* ctrl) {
4585 #ifdef _LP64
4586   // The scaled index operand to AddP must be a clean 64-bit value.
4587   // Java allows a 32-bit int to be incremented to a negative
4588   // value, which appears in a 64-bit register as a large
4589   // positive number.  Using that large positive number as an
4590   // operand in pointer arithmetic has bad consequences.
4591   // On the other hand, 32-bit overflow is rare, and the possibility
4592   // can often be excluded, if we annotate the ConvI2L node with
4593   // a type assertion that its value is known to be a small positive
4594   // number.  (The prior range check has ensured this.)
4595   // This assertion is used by ConvI2LNode::Ideal.
4596   int index_max = max_jint - 1;  // array size is max_jint, index is one less
4597   if (sizetype != nullptr && sizetype->_hi > 0) {
4598     index_max = sizetype->_hi - 1;
4599   }
4600   const TypeInt* iidxtype = TypeInt::make(0, index_max, Type::WidenMax);
4601   idx = constrained_convI2L(phase, idx, iidxtype, ctrl);
4602 #endif
4603   return idx;
4604 }
4605 
4606 // Convert integer value to a narrowed long type dependent on ctrl (for example, a range check)
4607 Node* Compile::constrained_convI2L(PhaseGVN* phase, Node* value, const TypeInt* itype, Node* ctrl, bool carry_dependency) {
4608   if (ctrl != nullptr) {
4609     // Express control dependency by a CastII node with a narrow type.
4610     // Make the CastII node dependent on the control input to prevent the narrowed ConvI2L
4611     // node from floating above the range check during loop optimizations. Otherwise, the
4612     // ConvI2L node may be eliminated independently of the range check, causing the data path
4613     // to become TOP while the control path is still there (although it's unreachable).
4614     value = new CastIINode(ctrl, value, itype, carry_dependency ? ConstraintCastNode::DependencyType::NonFloatingNarrowing : ConstraintCastNode::DependencyType::FloatingNarrowing, true /* range check dependency */);
4615     value = phase->transform(value);
4616   }
4617   const TypeLong* ltype = TypeLong::make(itype->_lo, itype->_hi, itype->_widen);
4618   return phase->transform(new ConvI2LNode(value, ltype));
4619 }
4620 
4621 void Compile::dump_print_inlining() {
4622   inline_printer()->print_on(tty);
4623 }
4624 
4625 void Compile::log_late_inline(CallGenerator* cg) {
4626   if (log() != nullptr) {
4627     log()->head("late_inline method='%d' inline_id='" JLONG_FORMAT "'", log()->identify(cg->method()),
4628                 cg->unique_id());
4629     JVMState* p = cg->call_node()->jvms();
4630     while (p != nullptr) {
4631       log()->elem("jvms bci='%d' method='%d'", p->bci(), log()->identify(p->method()));
4632       p = p->caller();
4633     }
4634     log()->tail("late_inline");
4635   }
4636 }
4637 
4638 void Compile::log_late_inline_failure(CallGenerator* cg, const char* msg) {
4639   log_late_inline(cg);
4640   if (log() != nullptr) {
4641     log()->inline_fail(msg);
4642   }
4643 }
4644 
4645 void Compile::log_inline_id(CallGenerator* cg) {
4646   if (log() != nullptr) {
4647     // The LogCompilation tool needs a unique way to identify late
4648     // inline call sites. This id must be unique for this call site in
4649     // this compilation. Try to have it unique across compilations as
4650     // well because it can be convenient when grepping through the log
4651     // file.
4652     // Distinguish OSR compilations from others in case CICountOSR is
4653     // on.
4654     jlong id = ((jlong)unique()) + (((jlong)compile_id()) << 33) + (CICountOSR && is_osr_compilation() ? ((jlong)1) << 32 : 0);
4655     cg->set_unique_id(id);
4656     log()->elem("inline_id id='" JLONG_FORMAT "'", id);
4657   }
4658 }
4659 
4660 void Compile::log_inline_failure(const char* msg) {
4661   if (C->log() != nullptr) {
4662     C->log()->inline_fail(msg);
4663   }
4664 }
4665 
4666 
4667 // Dump inlining replay data to the stream.
4668 // Don't change thread state and acquire any locks.
4669 void Compile::dump_inline_data(outputStream* out) {
4670   InlineTree* inl_tree = ilt();
4671   if (inl_tree != nullptr) {
4672     out->print(" inline %d", inl_tree->count());
4673     inl_tree->dump_replay_data(out);
4674   }
4675 }
4676 
4677 void Compile::dump_inline_data_reduced(outputStream* out) {
4678   assert(ReplayReduce, "");
4679 
4680   InlineTree* inl_tree = ilt();
4681   if (inl_tree == nullptr) {
4682     return;
4683   }
4684   // Enable iterative replay file reduction
4685   // Output "compile" lines for depth 1 subtrees,
4686   // simulating that those trees were compiled
4687   // instead of inlined.
4688   for (int i = 0; i < inl_tree->subtrees().length(); ++i) {
4689     InlineTree* sub = inl_tree->subtrees().at(i);
4690     if (sub->inline_level() != 1) {
4691       continue;
4692     }
4693 
4694     ciMethod* method = sub->method();
4695     int entry_bci = -1;
4696     int comp_level = env()->task()->comp_level();
4697     out->print("compile ");
4698     method->dump_name_as_ascii(out);
4699     out->print(" %d %d", entry_bci, comp_level);
4700     out->print(" inline %d", sub->count());
4701     sub->dump_replay_data(out, -1);
4702     out->cr();
4703   }
4704 }
4705 
4706 int Compile::cmp_expensive_nodes(Node* n1, Node* n2) {
4707   if (n1->Opcode() < n2->Opcode())      return -1;
4708   else if (n1->Opcode() > n2->Opcode()) return 1;
4709 
4710   assert(n1->req() == n2->req(), "can't compare %s nodes: n1->req() = %d, n2->req() = %d", NodeClassNames[n1->Opcode()], n1->req(), n2->req());
4711   for (uint i = 1; i < n1->req(); i++) {
4712     if (n1->in(i) < n2->in(i))      return -1;
4713     else if (n1->in(i) > n2->in(i)) return 1;
4714   }
4715 
4716   return 0;
4717 }
4718 
4719 int Compile::cmp_expensive_nodes(Node** n1p, Node** n2p) {
4720   Node* n1 = *n1p;
4721   Node* n2 = *n2p;
4722 
4723   return cmp_expensive_nodes(n1, n2);
4724 }
4725 
4726 void Compile::sort_expensive_nodes() {
4727   if (!expensive_nodes_sorted()) {
4728     _expensive_nodes.sort(cmp_expensive_nodes);
4729   }
4730 }
4731 
4732 bool Compile::expensive_nodes_sorted() const {
4733   for (int i = 1; i < _expensive_nodes.length(); i++) {
4734     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i-1)) < 0) {
4735       return false;
4736     }
4737   }
4738   return true;
4739 }
4740 
4741 bool Compile::should_optimize_expensive_nodes(PhaseIterGVN &igvn) {
4742   if (_expensive_nodes.length() == 0) {
4743     return false;
4744   }
4745 
4746   assert(OptimizeExpensiveOps, "optimization off?");
4747 
4748   // Take this opportunity to remove dead nodes from the list
4749   int j = 0;
4750   for (int i = 0; i < _expensive_nodes.length(); i++) {
4751     Node* n = _expensive_nodes.at(i);
4752     if (!n->is_unreachable(igvn)) {
4753       assert(n->is_expensive(), "should be expensive");
4754       _expensive_nodes.at_put(j, n);
4755       j++;
4756     }
4757   }
4758   _expensive_nodes.trunc_to(j);
4759 
4760   // Then sort the list so that similar nodes are next to each other
4761   // and check for at least two nodes of identical kind with same data
4762   // inputs.
4763   sort_expensive_nodes();
4764 
4765   for (int i = 0; i < _expensive_nodes.length()-1; i++) {
4766     if (cmp_expensive_nodes(_expensive_nodes.adr_at(i), _expensive_nodes.adr_at(i+1)) == 0) {
4767       return true;
4768     }
4769   }
4770 
4771   return false;
4772 }
4773 
4774 void Compile::cleanup_expensive_nodes(PhaseIterGVN &igvn) {
4775   if (_expensive_nodes.length() == 0) {
4776     return;
4777   }
4778 
4779   assert(OptimizeExpensiveOps, "optimization off?");
4780 
4781   // Sort to bring similar nodes next to each other and clear the
4782   // control input of nodes for which there's only a single copy.
4783   sort_expensive_nodes();
4784 
4785   int j = 0;
4786   int identical = 0;
4787   int i = 0;
4788   bool modified = false;
4789   for (; i < _expensive_nodes.length()-1; i++) {
4790     assert(j <= i, "can't write beyond current index");
4791     if (_expensive_nodes.at(i)->Opcode() == _expensive_nodes.at(i+1)->Opcode()) {
4792       identical++;
4793       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4794       continue;
4795     }
4796     if (identical > 0) {
4797       _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4798       identical = 0;
4799     } else {
4800       Node* n = _expensive_nodes.at(i);
4801       igvn.replace_input_of(n, 0, nullptr);
4802       igvn.hash_insert(n);
4803       modified = true;
4804     }
4805   }
4806   if (identical > 0) {
4807     _expensive_nodes.at_put(j++, _expensive_nodes.at(i));
4808   } else if (_expensive_nodes.length() >= 1) {
4809     Node* n = _expensive_nodes.at(i);
4810     igvn.replace_input_of(n, 0, nullptr);
4811     igvn.hash_insert(n);
4812     modified = true;
4813   }
4814   _expensive_nodes.trunc_to(j);
4815   if (modified) {
4816     igvn.optimize();
4817   }
4818 }
4819 
4820 void Compile::add_expensive_node(Node * n) {
4821   assert(!_expensive_nodes.contains(n), "duplicate entry in expensive list");
4822   assert(n->is_expensive(), "expensive nodes with non-null control here only");
4823   assert(!n->is_CFG() && !n->is_Mem(), "no cfg or memory nodes here");
4824   if (OptimizeExpensiveOps) {
4825     _expensive_nodes.append(n);
4826   } else {
4827     // Clear control input and let IGVN optimize expensive nodes if
4828     // OptimizeExpensiveOps is off.
4829     n->set_req(0, nullptr);
4830   }
4831 }
4832 
4833 /**
4834  * Track coarsened Lock and Unlock nodes.
4835  */
4836 
4837 class Lock_List : public Node_List {
4838   uint _origin_cnt;
4839 public:
4840   Lock_List(Arena *a, uint cnt) : Node_List(a), _origin_cnt(cnt) {}
4841   uint origin_cnt() const { return _origin_cnt; }
4842 };
4843 
4844 void Compile::add_coarsened_locks(GrowableArray<AbstractLockNode*>& locks) {
4845   int length = locks.length();
4846   if (length > 0) {
4847     // Have to keep this list until locks elimination during Macro nodes elimination.
4848     Lock_List* locks_list = new (comp_arena()) Lock_List(comp_arena(), length);
4849     AbstractLockNode* alock = locks.at(0);
4850     BoxLockNode* box = alock->box_node()->as_BoxLock();
4851     for (int i = 0; i < length; i++) {
4852       AbstractLockNode* lock = locks.at(i);
4853       assert(lock->is_coarsened(), "expecting only coarsened AbstractLock nodes, but got '%s'[%d] node", lock->Name(), lock->_idx);
4854       locks_list->push(lock);
4855       BoxLockNode* this_box = lock->box_node()->as_BoxLock();
4856       if (this_box != box) {
4857         // Locking regions (BoxLock) could be Unbalanced here:
4858         //  - its coarsened locks were eliminated in earlier
4859         //    macro nodes elimination followed by loop unroll
4860         //  - it is OSR locking region (no Lock node)
4861         // Preserve Unbalanced status in such cases.
4862         if (!this_box->is_unbalanced()) {
4863           this_box->set_coarsened();
4864         }
4865         if (!box->is_unbalanced()) {
4866           box->set_coarsened();
4867         }
4868       }
4869     }
4870     _coarsened_locks.append(locks_list);
4871   }
4872 }
4873 
4874 void Compile::remove_useless_coarsened_locks(Unique_Node_List& useful) {
4875   int count = coarsened_count();
4876   for (int i = 0; i < count; i++) {
4877     Node_List* locks_list = _coarsened_locks.at(i);
4878     for (uint j = 0; j < locks_list->size(); j++) {
4879       Node* lock = locks_list->at(j);
4880       assert(lock->is_AbstractLock(), "sanity");
4881       if (!useful.member(lock)) {
4882         locks_list->yank(lock);
4883       }
4884     }
4885   }
4886 }
4887 
4888 void Compile::remove_coarsened_lock(Node* n) {
4889   if (n->is_AbstractLock()) {
4890     int count = coarsened_count();
4891     for (int i = 0; i < count; i++) {
4892       Node_List* locks_list = _coarsened_locks.at(i);
4893       locks_list->yank(n);
4894     }
4895   }
4896 }
4897 
4898 bool Compile::coarsened_locks_consistent() {
4899   int count = coarsened_count();
4900   for (int i = 0; i < count; i++) {
4901     bool unbalanced = false;
4902     bool modified = false; // track locks kind modifications
4903     Lock_List* locks_list = (Lock_List*)_coarsened_locks.at(i);
4904     uint size = locks_list->size();
4905     if (size == 0) {
4906       unbalanced = false; // All locks were eliminated - good
4907     } else if (size != locks_list->origin_cnt()) {
4908       unbalanced = true; // Some locks were removed from list
4909     } else {
4910       for (uint j = 0; j < size; j++) {
4911         Node* lock = locks_list->at(j);
4912         // All nodes in group should have the same state (modified or not)
4913         if (!lock->as_AbstractLock()->is_coarsened()) {
4914           if (j == 0) {
4915             // first on list was modified, the rest should be too for consistency
4916             modified = true;
4917           } else if (!modified) {
4918             // this lock was modified but previous locks on the list were not
4919             unbalanced = true;
4920             break;
4921           }
4922         } else if (modified) {
4923           // previous locks on list were modified but not this lock
4924           unbalanced = true;
4925           break;
4926         }
4927       }
4928     }
4929     if (unbalanced) {
4930       // unbalanced monitor enter/exit - only some [un]lock nodes were removed or modified
4931 #ifdef ASSERT
4932       if (PrintEliminateLocks) {
4933         tty->print_cr("=== unbalanced coarsened locks ===");
4934         for (uint l = 0; l < size; l++) {
4935           locks_list->at(l)->dump();
4936         }
4937       }
4938 #endif
4939       record_failure(C2Compiler::retry_no_locks_coarsening());
4940       return false;
4941     }
4942   }
4943   return true;
4944 }
4945 
4946 // Mark locking regions (identified by BoxLockNode) as unbalanced if
4947 // locks coarsening optimization removed Lock/Unlock nodes from them.
4948 // Such regions become unbalanced because coarsening only removes part
4949 // of Lock/Unlock nodes in region. As result we can't execute other
4950 // locks elimination optimizations which assume all code paths have
4951 // corresponding pair of Lock/Unlock nodes - they are balanced.
4952 void Compile::mark_unbalanced_boxes() const {
4953   int count = coarsened_count();
4954   for (int i = 0; i < count; i++) {
4955     Node_List* locks_list = _coarsened_locks.at(i);
4956     uint size = locks_list->size();
4957     if (size > 0) {
4958       AbstractLockNode* alock = locks_list->at(0)->as_AbstractLock();
4959       BoxLockNode* box = alock->box_node()->as_BoxLock();
4960       if (alock->is_coarsened()) {
4961         // coarsened_locks_consistent(), which is called before this method, verifies
4962         // that the rest of Lock/Unlock nodes on locks_list are also coarsened.
4963         assert(!box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4964         for (uint j = 1; j < size; j++) {
4965           assert(locks_list->at(j)->as_AbstractLock()->is_coarsened(), "only coarsened locks are expected here");
4966           BoxLockNode* this_box = locks_list->at(j)->as_AbstractLock()->box_node()->as_BoxLock();
4967           if (box != this_box) {
4968             assert(!this_box->is_eliminated(), "regions with coarsened locks should not be marked as eliminated");
4969             box->set_unbalanced();
4970             this_box->set_unbalanced();
4971           }
4972         }
4973       }
4974     }
4975   }
4976 }
4977 
4978 /**
4979  * Remove the speculative part of types and clean up the graph
4980  */
4981 void Compile::remove_speculative_types(PhaseIterGVN &igvn) {
4982   if (UseTypeSpeculation) {
4983     Unique_Node_List worklist;
4984     worklist.push(root());
4985     int modified = 0;
4986     // Go over all type nodes that carry a speculative type, drop the
4987     // speculative part of the type and enqueue the node for an igvn
4988     // which may optimize it out.
4989     for (uint next = 0; next < worklist.size(); ++next) {
4990       Node *n  = worklist.at(next);
4991       if (n->is_Type()) {
4992         TypeNode* tn = n->as_Type();
4993         const Type* t = tn->type();
4994         const Type* t_no_spec = t->remove_speculative();
4995         if (t_no_spec != t) {
4996           bool in_hash = igvn.hash_delete(n);
4997           assert(in_hash || n->hash() == Node::NO_HASH, "node should be in igvn hash table");
4998           tn->set_type(t_no_spec);
4999           igvn.hash_insert(n);
5000           igvn._worklist.push(n); // give it a chance to go away
5001           modified++;
5002         }
5003       }
5004       // Iterate over outs - endless loops is unreachable from below
5005       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5006         Node *m = n->fast_out(i);
5007         if (not_a_node(m)) {
5008           continue;
5009         }
5010         worklist.push(m);
5011       }
5012     }
5013     // Drop the speculative part of all types in the igvn's type table
5014     igvn.remove_speculative_types();
5015     if (modified > 0) {
5016       igvn.optimize();
5017       if (failing())  return;
5018     }
5019 #ifdef ASSERT
5020     // Verify that after the IGVN is over no speculative type has resurfaced
5021     worklist.clear();
5022     worklist.push(root());
5023     for (uint next = 0; next < worklist.size(); ++next) {
5024       Node *n  = worklist.at(next);
5025       const Type* t = igvn.type_or_null(n);
5026       assert((t == nullptr) || (t == t->remove_speculative()), "no more speculative types");
5027       if (n->is_Type()) {
5028         t = n->as_Type()->type();
5029         assert(t == t->remove_speculative(), "no more speculative types");
5030       }
5031       // Iterate over outs - endless loops is unreachable from below
5032       for (DUIterator_Fast imax, i = n->fast_outs(imax); i < imax; i++) {
5033         Node *m = n->fast_out(i);
5034         if (not_a_node(m)) {
5035           continue;
5036         }
5037         worklist.push(m);
5038       }
5039     }
5040     igvn.check_no_speculative_types();
5041 #endif
5042   }
5043 }
5044 
5045 // Auxiliary methods to support randomized stressing/fuzzing.
5046 
5047 void Compile::initialize_stress_seed(const DirectiveSet* directive) {
5048   if (FLAG_IS_DEFAULT(StressSeed) || (FLAG_IS_ERGO(StressSeed) && directive->RepeatCompilationOption)) {
5049     _stress_seed = static_cast<uint>(Ticks::now().nanoseconds());
5050     FLAG_SET_ERGO(StressSeed, _stress_seed);
5051   } else {
5052     _stress_seed = StressSeed;
5053   }
5054   if (_log != nullptr) {
5055     _log->elem("stress_test seed='%u'", _stress_seed);
5056   }
5057 }
5058 
5059 int Compile::random() {
5060   _stress_seed = os::next_random(_stress_seed);
5061   return static_cast<int>(_stress_seed);
5062 }
5063 
5064 // This method can be called the arbitrary number of times, with current count
5065 // as the argument. The logic allows selecting a single candidate from the
5066 // running list of candidates as follows:
5067 //    int count = 0;
5068 //    Cand* selected = null;
5069 //    while(cand = cand->next()) {
5070 //      if (randomized_select(++count)) {
5071 //        selected = cand;
5072 //      }
5073 //    }
5074 //
5075 // Including count equalizes the chances any candidate is "selected".
5076 // This is useful when we don't have the complete list of candidates to choose
5077 // from uniformly. In this case, we need to adjust the randomicity of the
5078 // selection, or else we will end up biasing the selection towards the latter
5079 // candidates.
5080 //
5081 // Quick back-envelope calculation shows that for the list of n candidates
5082 // the equal probability for the candidate to persist as "best" can be
5083 // achieved by replacing it with "next" k-th candidate with the probability
5084 // of 1/k. It can be easily shown that by the end of the run, the
5085 // probability for any candidate is converged to 1/n, thus giving the
5086 // uniform distribution among all the candidates.
5087 //
5088 // We don't care about the domain size as long as (RANDOMIZED_DOMAIN / count) is large.
5089 #define RANDOMIZED_DOMAIN_POW 29
5090 #define RANDOMIZED_DOMAIN (1 << RANDOMIZED_DOMAIN_POW)
5091 #define RANDOMIZED_DOMAIN_MASK ((1 << (RANDOMIZED_DOMAIN_POW + 1)) - 1)
5092 bool Compile::randomized_select(int count) {
5093   assert(count > 0, "only positive");
5094   return (random() & RANDOMIZED_DOMAIN_MASK) < (RANDOMIZED_DOMAIN / count);
5095 }
5096 
5097 #ifdef ASSERT
5098 // Failures are geometrically distributed with probability 1/StressBailoutMean.
5099 bool Compile::fail_randomly() {
5100   if ((random() % StressBailoutMean) != 0) {
5101     return false;
5102   }
5103   record_failure("StressBailout");
5104   return true;
5105 }
5106 
5107 bool Compile::failure_is_artificial() {
5108   return C->failure_reason_is("StressBailout");
5109 }
5110 #endif
5111 
5112 CloneMap&     Compile::clone_map()                 { return _clone_map; }
5113 void          Compile::set_clone_map(Dict* d)      { _clone_map._dict = d; }
5114 
5115 void NodeCloneInfo::dump_on(outputStream* st) const {
5116   st->print(" {%d:%d} ", idx(), gen());
5117 }
5118 
5119 void CloneMap::clone(Node* old, Node* nnn, int gen) {
5120   uint64_t val = value(old->_idx);
5121   NodeCloneInfo cio(val);
5122   assert(val != 0, "old node should be in the map");
5123   NodeCloneInfo cin(cio.idx(), gen + cio.gen());
5124   insert(nnn->_idx, cin.get());
5125 #ifndef PRODUCT
5126   if (is_debug()) {
5127     tty->print_cr("CloneMap::clone inserted node %d info {%d:%d} into CloneMap", nnn->_idx, cin.idx(), cin.gen());
5128   }
5129 #endif
5130 }
5131 
5132 void CloneMap::verify_insert_and_clone(Node* old, Node* nnn, int gen) {
5133   NodeCloneInfo cio(value(old->_idx));
5134   if (cio.get() == 0) {
5135     cio.set(old->_idx, 0);
5136     insert(old->_idx, cio.get());
5137 #ifndef PRODUCT
5138     if (is_debug()) {
5139       tty->print_cr("CloneMap::verify_insert_and_clone inserted node %d info {%d:%d} into CloneMap", old->_idx, cio.idx(), cio.gen());
5140     }
5141 #endif
5142   }
5143   clone(old, nnn, gen);
5144 }
5145 
5146 int CloneMap::max_gen() const {
5147   int g = 0;
5148   DictI di(_dict);
5149   for(; di.test(); ++di) {
5150     int t = gen(di._key);
5151     if (g < t) {
5152       g = t;
5153 #ifndef PRODUCT
5154       if (is_debug()) {
5155         tty->print_cr("CloneMap::max_gen() update max=%d from %d", g, _2_node_idx_t(di._key));
5156       }
5157 #endif
5158     }
5159   }
5160   return g;
5161 }
5162 
5163 void CloneMap::dump(node_idx_t key, outputStream* st) const {
5164   uint64_t val = value(key);
5165   if (val != 0) {
5166     NodeCloneInfo ni(val);
5167     ni.dump_on(st);
5168   }
5169 }
5170 
5171 void Compile::shuffle_macro_nodes() {
5172   shuffle_array(*C, _macro_nodes);
5173 }
5174 
5175 // Move Allocate nodes to the start of the list
5176 void Compile::sort_macro_nodes() {
5177   int count = macro_count();
5178   int allocates = 0;
5179   for (int i = 0; i < count; i++) {
5180     Node* n = macro_node(i);
5181     if (n->is_Allocate()) {
5182       if (i != allocates) {
5183         Node* tmp = macro_node(allocates);
5184         _macro_nodes.at_put(allocates, n);
5185         _macro_nodes.at_put(i, tmp);
5186       }
5187       allocates++;
5188     }
5189   }
5190 }
5191 
5192 void Compile::print_method(CompilerPhaseType compile_phase, int level, Node* n) {
5193   if (failing_internal()) { return; } // failing_internal to not stress bailouts from printing code.
5194   EventCompilerPhase event(UNTIMED);
5195   if (event.should_commit()) {
5196     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, compile_phase, C->_compile_id, level);
5197   }
5198 #ifndef PRODUCT
5199   ResourceMark rm;
5200   stringStream ss;
5201   ss.print_raw(CompilerPhaseTypeHelper::to_description(compile_phase));
5202   int iter = ++_igv_phase_iter[compile_phase];
5203   if (iter > 1) {
5204     ss.print(" %d", iter);
5205   }
5206   if (n != nullptr) {
5207     ss.print(": %d %s", n->_idx, NodeClassNames[n->Opcode()]);
5208     if (n->is_Call()) {
5209       CallNode* call = n->as_Call();
5210       if (call->_name != nullptr) {
5211         // E.g. uncommon traps etc.
5212         ss.print(" - %s", call->_name);
5213       } else if (call->is_CallJava()) {
5214         CallJavaNode* call_java = call->as_CallJava();
5215         if (call_java->method() != nullptr) {
5216           ss.print(" -");
5217           call_java->method()->print_short_name(&ss);
5218         }
5219       }
5220     }
5221   }
5222 
5223   const char* name = ss.as_string();
5224   if (should_print_igv(level)) {
5225     _igv_printer->print_graph(name);
5226   }
5227   if (should_print_phase(level)) {
5228     print_phase(name);
5229   }
5230   if (should_print_ideal_phase(compile_phase)) {
5231     print_ideal_ir(CompilerPhaseTypeHelper::to_name(compile_phase));
5232   }
5233 #endif
5234   C->_latest_stage_start_counter.stamp();
5235 }
5236 
5237 // Only used from CompileWrapper
5238 void Compile::begin_method() {
5239 #ifndef PRODUCT
5240   if (_method != nullptr && should_print_igv(1)) {
5241     _igv_printer->begin_method();
5242   }
5243 #endif
5244   C->_latest_stage_start_counter.stamp();
5245 }
5246 
5247 // Only used from CompileWrapper
5248 void Compile::end_method() {
5249   EventCompilerPhase event(UNTIMED);
5250   if (event.should_commit()) {
5251     CompilerEvent::PhaseEvent::post(event, C->_latest_stage_start_counter, PHASE_END, C->_compile_id, 1);
5252   }
5253 
5254 #ifndef PRODUCT
5255   if (_method != nullptr && should_print_igv(1)) {
5256     _igv_printer->end_method();
5257   }
5258 #endif
5259 }
5260 
5261 #ifndef PRODUCT
5262 bool Compile::should_print_phase(const int level) const {
5263   return PrintPhaseLevel >= 0 && directive()->PhasePrintLevelOption >= level &&
5264          _method != nullptr; // Do not print phases for stubs.
5265 }
5266 
5267 bool Compile::should_print_ideal_phase(CompilerPhaseType cpt) const {
5268   return _directive->should_print_ideal_phase(cpt);
5269 }
5270 
5271 void Compile::init_igv() {
5272   if (_igv_printer == nullptr) {
5273     _igv_printer = IdealGraphPrinter::printer();
5274     _igv_printer->set_compile(this);
5275   }
5276 }
5277 
5278 bool Compile::should_print_igv(const int level) {
5279   PRODUCT_RETURN_(return false;);
5280 
5281   if (PrintIdealGraphLevel < 0) { // disabled by the user
5282     return false;
5283   }
5284 
5285   bool need = directive()->IGVPrintLevelOption >= level;
5286   if (need) {
5287     Compile::init_igv();
5288   }
5289   return need;
5290 }
5291 
5292 IdealGraphPrinter* Compile::_debug_file_printer = nullptr;
5293 IdealGraphPrinter* Compile::_debug_network_printer = nullptr;
5294 
5295 // Called from debugger. Prints method to the default file with the default phase name.
5296 // This works regardless of any Ideal Graph Visualizer flags set or not.
5297 // Use in debugger (gdb/rr): p igv_print($sp, $fp, $pc).
5298 void igv_print(void* sp, void* fp, void* pc) {
5299   frame fr(sp, fp, pc);
5300   Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5301 }
5302 
5303 // Same as igv_print() above but with a specified phase name.
5304 void igv_print(const char* phase_name, void* sp, void* fp, void* pc) {
5305   frame fr(sp, fp, pc);
5306   Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5307 }
5308 
5309 // Called from debugger. Prints method with the default phase name to the default network or the one specified with
5310 // the network flags for the Ideal Graph Visualizer, or to the default file depending on the 'network' argument.
5311 // This works regardless of any Ideal Graph Visualizer flags set or not.
5312 // Use in debugger (gdb/rr): p igv_print(true, $sp, $fp, $pc).
5313 void igv_print(bool network, void* sp, void* fp, void* pc) {
5314   frame fr(sp, fp, pc);
5315   if (network) {
5316     Compile::current()->igv_print_method_to_network(nullptr, &fr);
5317   } else {
5318     Compile::current()->igv_print_method_to_file(nullptr, false, &fr);
5319   }
5320 }
5321 
5322 // Same as igv_print(bool network, ...) above but with a specified phase name.
5323 // Use in debugger (gdb/rr): p igv_print(true, "MyPhase", $sp, $fp, $pc).
5324 void igv_print(bool network, const char* phase_name, void* sp, void* fp, void* pc) {
5325   frame fr(sp, fp, pc);
5326   if (network) {
5327     Compile::current()->igv_print_method_to_network(phase_name, &fr);
5328   } else {
5329     Compile::current()->igv_print_method_to_file(phase_name, false, &fr);
5330   }
5331 }
5332 
5333 // Called from debugger. Normal write to the default _printer. Only works if Ideal Graph Visualizer printing flags are set.
5334 void igv_print_default() {
5335   Compile::current()->print_method(PHASE_DEBUG, 0);
5336 }
5337 
5338 // Called from debugger, especially when replaying a trace in which the program state cannot be altered like with rr replay.
5339 // A method is appended to an existing default file with the default phase name. This means that igv_append() must follow
5340 // an earlier igv_print(*) call which sets up the file. This works regardless of any Ideal Graph Visualizer flags set or not.
5341 // Use in debugger (gdb/rr): p igv_append($sp, $fp, $pc).
5342 void igv_append(void* sp, void* fp, void* pc) {
5343   frame fr(sp, fp, pc);
5344   Compile::current()->igv_print_method_to_file(nullptr, true, &fr);
5345 }
5346 
5347 // Same as igv_append(...) above but with a specified phase name.
5348 // Use in debugger (gdb/rr): p igv_append("MyPhase", $sp, $fp, $pc).
5349 void igv_append(const char* phase_name, void* sp, void* fp, void* pc) {
5350   frame fr(sp, fp, pc);
5351   Compile::current()->igv_print_method_to_file(phase_name, true, &fr);
5352 }
5353 
5354 void Compile::igv_print_method_to_file(const char* phase_name, bool append, const frame* fr) {
5355   const char* file_name = "custom_debug.xml";
5356   if (_debug_file_printer == nullptr) {
5357     _debug_file_printer = new IdealGraphPrinter(C, file_name, append);
5358   } else {
5359     _debug_file_printer->update_compiled_method(C->method());
5360   }
5361   tty->print_cr("Method %s to %s", append ? "appended" : "printed", file_name);
5362   _debug_file_printer->print_graph(phase_name, fr);
5363 }
5364 
5365 void Compile::igv_print_method_to_network(const char* phase_name, const frame* fr) {
5366   ResourceMark rm;
5367   GrowableArray<const Node*> empty_list;
5368   igv_print_graph_to_network(phase_name, empty_list, fr);
5369 }
5370 
5371 void Compile::igv_print_graph_to_network(const char* name, GrowableArray<const Node*>& visible_nodes, const frame* fr) {
5372   if (_debug_network_printer == nullptr) {
5373     _debug_network_printer = new IdealGraphPrinter(C);
5374   } else {
5375     _debug_network_printer->update_compiled_method(C->method());
5376   }
5377   tty->print_cr("Method printed over network stream to IGV");
5378   _debug_network_printer->print(name, C->root(), visible_nodes, fr);
5379 }
5380 #endif // !PRODUCT
5381 
5382 Node* Compile::narrow_value(BasicType bt, Node* value, const Type* type, PhaseGVN* phase, bool transform_res) {
5383   if (type != nullptr && phase->type(value)->higher_equal(type)) {
5384     return value;
5385   }
5386   Node* result = nullptr;
5387   if (bt == T_BYTE) {
5388     result = phase->transform(new LShiftINode(value, phase->intcon(24)));
5389     result = new RShiftINode(result, phase->intcon(24));
5390   } else if (bt == T_BOOLEAN) {
5391     result = new AndINode(value, phase->intcon(0xFF));
5392   } else if (bt == T_CHAR) {
5393     result = new AndINode(value,phase->intcon(0xFFFF));
5394   } else {
5395     assert(bt == T_SHORT, "unexpected narrow type");
5396     result = phase->transform(new LShiftINode(value, phase->intcon(16)));
5397     result = new RShiftINode(result, phase->intcon(16));
5398   }
5399   if (transform_res) {
5400     result = phase->transform(result);
5401   }
5402   return result;
5403 }
5404 
5405 void Compile::record_method_not_compilable_oom() {
5406   record_method_not_compilable(CompilationMemoryStatistic::failure_reason_memlimit());
5407 }
5408 
5409 #ifndef PRODUCT
5410 // Collects all the control inputs from nodes on the worklist and from their data dependencies
5411 static void find_candidate_control_inputs(Unique_Node_List& worklist, Unique_Node_List& candidates) {
5412   // Follow non-control edges until we reach CFG nodes
5413   for (uint i = 0; i < worklist.size(); i++) {
5414     const Node* n = worklist.at(i);
5415     for (uint j = 0; j < n->req(); j++) {
5416       Node* in = n->in(j);
5417       if (in == nullptr || in->is_Root()) {
5418         continue;
5419       }
5420       if (in->is_CFG()) {
5421         if (in->is_Call()) {
5422           // The return value of a call is only available if the call did not result in an exception
5423           Node* control_proj_use = in->as_Call()->proj_out(TypeFunc::Control)->unique_out();
5424           if (control_proj_use->is_Catch()) {
5425             Node* fall_through = control_proj_use->as_Catch()->proj_out(CatchProjNode::fall_through_index);
5426             candidates.push(fall_through);
5427             continue;
5428           }
5429         }
5430 
5431         if (in->is_Multi()) {
5432           // We got here by following data inputs so we should only have one control use
5433           // (no IfNode, etc)
5434           assert(!n->is_MultiBranch(), "unexpected node type: %s", n->Name());
5435           candidates.push(in->as_Multi()->proj_out(TypeFunc::Control));
5436         } else {
5437           candidates.push(in);
5438         }
5439       } else {
5440         worklist.push(in);
5441       }
5442     }
5443   }
5444 }
5445 
5446 // Returns the candidate node that is a descendant to all the other candidates
5447 static Node* pick_control(Unique_Node_List& candidates) {
5448   Unique_Node_List worklist;
5449   worklist.copy(candidates);
5450 
5451   // Traverse backwards through the CFG
5452   for (uint i = 0; i < worklist.size(); i++) {
5453     const Node* n = worklist.at(i);
5454     if (n->is_Root()) {
5455       continue;
5456     }
5457     for (uint j = 0; j < n->req(); j++) {
5458       // Skip backedge of loops to avoid cycles
5459       if (n->is_Loop() && j == LoopNode::LoopBackControl) {
5460         continue;
5461       }
5462 
5463       Node* pred = n->in(j);
5464       if (pred != nullptr && pred != n && pred->is_CFG()) {
5465         worklist.push(pred);
5466         // if pred is an ancestor of n, then pred is an ancestor to at least one candidate
5467         candidates.remove(pred);
5468       }
5469     }
5470   }
5471 
5472   assert(candidates.size() == 1, "unexpected control flow");
5473   return candidates.at(0);
5474 }
5475 
5476 // Initialize a parameter input for a debug print call, using a placeholder for jlong and jdouble
5477 static void debug_print_init_parm(Node* call, Node* parm, Node* half, int* pos) {
5478   call->init_req((*pos)++, parm);
5479   const BasicType bt = parm->bottom_type()->basic_type();
5480   if (bt == T_LONG || bt == T_DOUBLE) {
5481     call->init_req((*pos)++, half);
5482   }
5483 }
5484 
5485 Node* Compile::make_debug_print_call(const char* str, address call_addr, PhaseGVN* gvn,
5486                               Node* parm0, Node* parm1,
5487                               Node* parm2, Node* parm3,
5488                               Node* parm4, Node* parm5,
5489                               Node* parm6) const {
5490   Node* str_node = gvn->transform(new ConPNode(TypeRawPtr::make(((address) str))));
5491   const TypeFunc* type = OptoRuntime::debug_print_Type(parm0, parm1, parm2, parm3, parm4, parm5, parm6);
5492   Node* call = new CallLeafNode(type, call_addr, "debug_print", TypeRawPtr::BOTTOM);
5493 
5494   // find the most suitable control input
5495   Unique_Node_List worklist, candidates;
5496   if (parm0 != nullptr) { worklist.push(parm0);
5497   if (parm1 != nullptr) { worklist.push(parm1);
5498   if (parm2 != nullptr) { worklist.push(parm2);
5499   if (parm3 != nullptr) { worklist.push(parm3);
5500   if (parm4 != nullptr) { worklist.push(parm4);
5501   if (parm5 != nullptr) { worklist.push(parm5);
5502   if (parm6 != nullptr) { worklist.push(parm6);
5503   /* close each nested if ===> */  } } } } } } }
5504   find_candidate_control_inputs(worklist, candidates);
5505   Node* control = nullptr;
5506   if (candidates.size() == 0) {
5507     control = C->start()->proj_out(TypeFunc::Control);
5508   } else {
5509     control = pick_control(candidates);
5510   }
5511 
5512   // find all the previous users of the control we picked
5513   GrowableArray<Node*> users_of_control;
5514   for (DUIterator_Fast kmax, i = control->fast_outs(kmax); i < kmax; i++) {
5515     Node* use = control->fast_out(i);
5516     if (use->is_CFG() && use != control) {
5517       users_of_control.push(use);
5518     }
5519   }
5520 
5521   // we do not actually care about IO and memory as it uses neither
5522   call->init_req(TypeFunc::Control,   control);
5523   call->init_req(TypeFunc::I_O,       top());
5524   call->init_req(TypeFunc::Memory,    top());
5525   call->init_req(TypeFunc::FramePtr,  C->start()->proj_out(TypeFunc::FramePtr));
5526   call->init_req(TypeFunc::ReturnAdr, top());
5527 
5528   int pos = TypeFunc::Parms;
5529   call->init_req(pos++, str_node);
5530   if (parm0 != nullptr) { debug_print_init_parm(call, parm0, top(), &pos);
5531   if (parm1 != nullptr) { debug_print_init_parm(call, parm1, top(), &pos);
5532   if (parm2 != nullptr) { debug_print_init_parm(call, parm2, top(), &pos);
5533   if (parm3 != nullptr) { debug_print_init_parm(call, parm3, top(), &pos);
5534   if (parm4 != nullptr) { debug_print_init_parm(call, parm4, top(), &pos);
5535   if (parm5 != nullptr) { debug_print_init_parm(call, parm5, top(), &pos);
5536   if (parm6 != nullptr) { debug_print_init_parm(call, parm6, top(), &pos);
5537   /* close each nested if ===> */  } } } } } } }
5538   assert(call->in(call->req()-1) != nullptr, "must initialize all parms");
5539 
5540   call = gvn->transform(call);
5541   Node* call_control_proj = gvn->transform(new ProjNode(call, TypeFunc::Control));
5542 
5543   // rewire previous users to have the new call as control instead
5544   PhaseIterGVN* igvn = gvn->is_IterGVN();
5545   for (int i = 0; i < users_of_control.length(); i++) {
5546     Node* use = users_of_control.at(i);
5547     for (uint j = 0; j < use->req(); j++) {
5548       if (use->in(j) == control) {
5549         if (igvn != nullptr) {
5550           igvn->replace_input_of(use, j, call_control_proj);
5551         } else {
5552           gvn->hash_delete(use);
5553           use->set_req(j, call_control_proj);
5554           gvn->hash_insert(use);
5555         }
5556       }
5557     }
5558   }
5559 
5560   return call;
5561 }
5562 #endif // !PRODUCT